In the Bible, the verses talking of infants, babes and children all point to the fact they are also part of God’s Kingdom, and acceptable to Jesus. They are examples of perfect members ‘of the Kingdom’ set forth by Jesus to the world to follow. The kingdom is taken from the unworthy caretakers and entrusted to new husbandmen (Lk 20:9-16). In the kingdom of the Old Testament or the Old Covenant, infants were also part of the kingdom, the holy nation.

In the prophecy about the new testament church or congregation, God says,

Jer:30:19: And out of them shall proceed thanksgiving and the voice of them that make merry: and I will multiply them, and they shall not be few; I will also glorify them, and they shall not be small. Jer:30:20: Their children also shall be as aforetime, and their congregation shall be established before me, and I will punish all that oppress them. Jer:30:21: And their nobles shall be of themselves, and their governor shall proceed from the midst of them; and I will cause him to draw near, and he shall approach unto me: for who is this that engaged his heart to approach unto me?  saith the LORD. Jer:30:22: And ye shall be my people, and I will be your God.

Jer:31:8: Behold, I will bring them from the north country, and gather them from the coasts of the earth, and with them the blind and the lame, the woman with child and her that travaileth with child together: a great company shall return thither.

Jer:32:27: Behold, I am the LORD, the God of all flesh: is there any thing too hard for me?

Even in the prophecy of the Kingdom ‘children that give suck’ are undoubtedly part of the Kingdom.

Isa:11:1-9: And there shall come forth a rod out of the stem of Jesse, and a Branch shall grow out of his roots: And the spirit of the LORD shall rest upon him, the spirit of wisdom and understanding, the spirit of counsel and might, the spirit of knowledge and of the fear of the LORD; And shall make him of quick understanding in the fear of the LORD: and he shall not judge after the sight of his eyes, neither reprove after the hearing of his ears: But with righteousness shall he judge the poor, and reprove with equity for the meek of the earth: and he shall smite the earth with the rod of his mouth, and with the breath of his lips shall he slay the wicked.And righteousness shall be the girdle of his loins, and faithfulness the girdle of his reins. The wolf also shall dwell with the lamb, and the leopard shall lie down with the kid; and the calf and the young lion and the fatling together; and a little child shall lead them.And the cow and the bear shall feed; their young ones shall lie down together: and the lion shall eat straw like the ox. And the sucking child shall play on the hole of the asp, and the weaned child shall put his hand on the cockatrice' den. They shall not hurt nor destroy in all my holy mountain: for the earth shall be full of the knowledge of the LORD, as the waters cover the sea.

Isa:40:10: Behold, the Lord GOD will come with strong hand, and his arm shall rule for him: behold, his reward is with him, and his work before him. Isa:40:11: He shall feed his flock like a shepherd: he shall gather the lambs with his arm, and carry them in his bosom, and shall gently lead those that are with young.

Some Scriptures which support "infant faith" are these:

Job 10:8 - "your hands have formed me and fashioned me; will you then turn and destroy me?"

Psalms:22:9: But thou art he that took me out of the womb: thou didst make me hope when I was upon my mother's breasts. Psalms:22:10: I was cast upon thee from the womb: thou art my God from my mother's belly.

Psalms:71:6: By thee have I been holden up from the womb: thou art he that took me out of my mother's bowels: my praise shall be continually of thee.

Psalms:127:3: Lo, children are an heritage of the LORD: and the fruit of the womb is his reward.

Psalms:139:13: For thou hast possessed my reins: thou hast covered me in my mother's womb.

Isa:44:2: Thus saith the LORD that made thee, and formed thee from the womb, which will help thee; Fear not, O Jacob, my servant; and thou, Jesurun, whom I have chosen.

Isa:44:24: Thus saith the LORD, thy redeemer, and he that formed thee from the womb, I am the LORD that maketh all things; that stretcheth forth the heavens alone; that spreadeth abroad the earth by myself;

Isa:46:3: Hearken unto me, O house of Jacob, and all the remnant of the house of Israel, which are borne by me from the belly, which are carried from the womb:

M't:18:1: At the same time came the disciples unto Jesus, saying, Who is the greatest in the kingdom of heaven? M't:18:2: And Jesus called a little child unto him, and set him in the midst of them, M't:18:3: And said, Verily I say unto you, Except ye be converted, and become as little children, ye shall not enter into the kingdom of heaven. M't:18:4: Whosoever therefore shall humble himself as this little child, the same is greatest in the kingdom of heaven. M't:18:5: And whoso shall receive one such little child in my name receiveth me. M't:18:6: But whoso shall offend one of these little ones which believe in me, it were better for him that a millstone were hanged about his neck, and that he were drowned in the depth of the sea.

M't:18:10: Take heed that ye despise not one of these little ones; for I say unto you, That in heaven their angels do always behold the face of my Father which is in heaven.M't:18:11: For the Son of man is come to save that which was lost.

M't:18:14: Even so it is not the will of your Father which is in heaven, that one of these little ones should perish.

M't:21:16: And said unto him, Hearest thou what these say? And Jesus saith unto them, Yea; have ye never read, Out of the mouth of babes and sucklings thou hast perfected praise?

M'r:9:37: Whosoever shall receive one of such children in my name, receiveth me: and whosoever shall receive me, receiveth not me, but him that sent me.

M'r:9:42: And whosoever shall offend one of these little ones that believe in me, it is better for him that a millstone were hanged about his neck, and he were cast into the sea.

M'r:10:13-15: And they brought young children to him, that he should touch them: and his disciples rebuked those that brought them.But when Jesus saw it, he was much displeased, and said unto them, Suffer the little children to come unto me, and forbid them not: for of such is the kingdom of God. Verily I say unto you, Whosoever shall not receive the kingdom of God as a little child, he shall not enter therein.

Luke 1:44"For behold, when the sound of your greeting [Theotokos] reached my ears [Elizabeth], the baby [John the Baptist] leaped in my womb for joy."

Lu:17:2: It were better for him that a millstone were hanged about his neck, and he cast into the sea, than that he should offend one of these little ones.

1Co:7:12: But to the rest speak I, not the Lord: If any brother hath a wife that believeth not, and she be pleased to dwell with him, let him not put her away.1Co:7:13: And the woman which hath an husband that believeth not, and if he be pleased to dwell with her, let her not leave him. 1Co:7:14: For the unbelieving husband is sanctified by the wife, and the unbelieving wife is sanctified by the husband: else were your children unclean; but now are they holy.

St. Paul in 1Cor 7:12-14, addressing the Gentile church at Corinth says the children of believing parents are born holy. Some bible translations have instead of ‘holy’, ‘acceptable to God’ (santos, santi agio, etc in Spanish, etc) which shows the meaning of the verse here. St. Paul here is reminding of the tradition Jewish belief from scripture that once joined to the community of God, the resultant offspring is part of the holy nation. Then meaning God accepts them, then why deny baptism to a believer’s child?

Malachi 2:15 Has not the one God made you? You belong to him in body and spirit. And what does the one God seek? Godly offspring. So be on your guard, and do not be unfaithful to the wife of your youth.

The Greek Bible uses hagios (hag'-ee-os) meaning ἁγία ἅγιαι ἁγίαις ἁγίαν ἁγίας ἅγιε ἅγιοι ἁγίοις ἅγιον ἅγιος ἁγίου ἁγίους ἁγίῳ ἁγίων ἁγιωτάτῃ meaning sacred (physically, pure, morally blameless or religious, ceremonially, consecrated) -- (most) holy (one, thing), saint.

Strong's Greek:  hagios (hag'-ee-os)

1Cor 7:14 states that the sanctification of the parent is proven by the fact that the offspring is holy.

The word the word a{gio" (hagios) in the Bible for “saint” or “saints” is also translated “sanctified” or “holy ones.” The root word hazo, means “to venerate.”

Hagios means to be separated from sin and therefore consecrated to God.

Our words “holy” and “holiness” come from the Hebrew (qadosh and qodesh) from the Greek (hagios, hagiosyne) and the Latin (sanctitas, sacer, sanctus).

Essentially holy means what is divine and pertains to God. It is His most intimate essence in which He radically transcends all that is created; totally Other.

The phraseology accords with that of the Jews, who regarded the heathen as "unclean," and all of the elect nation as "holy," that is, partakers of the holy covenant. Children were included in the covenant, as God made it not only with Abraham, but with his "seed after" him (Ge 17:7). So the faith of one Christian parent gives to the children a near relationship to the Church, just as if both parents were Christians (compare Ro 11:16). Paul appeals to the Corinthians as recognizing the principle, that the infants of heathen parents would not be admissible to Christian baptism, because there is no faith on the part of the parents; but where one parent is a believer, the children are regarded as not aliens from, but admissible even in infancy as sharers in, the Christian covenant: for the Church presumes that the believing parent will rear the child in the Christian faith. Infant baptism tacitly superseded infant circumcision, just as the Christian Lord's day gradually superseded the Jewish sabbath, without our having any express command for, or record of, transference. The setting aside of circumcision and of sabbaths in the case of the Gentiles was indeed expressly commanded by the apostles and Paul, but the substitution of infant baptism and of the Lord's day were tacitly adopted, not expressly enacted. No explicit mention of it occurs till Irenæus in the third century; but no society of Christians that we read of disputed its propriety till fifteen hundred years after Christ. Anabaptists would have us defer baptism till maturity as the child cannot understand the nature of it. But a child may be made heir of an estate: it is his, though incapable at the time of using or comprehending its advantage; he is not hereafter to acquire the title and claim to it: he will hereafter understand his claim, and be capable of employing his wealth: he will then, moreover, become responsible for the use he makes of it [Archbishop Whately].

That the unbelieving husband might more easily be sanctified, or become a Christian, by being connected with a Christian wife (according to Rosenmuller and Schleusner), because he is speaking of something in the connection which made the children holy; and because the word ἁγιάζω hagiazō is not used in this sense elsewhere. Else were your children unclean - (ἀκάθαρτα akatharta). Impure; the opposite of what is meant by holy.

If we consider the apostle as speaking of the children of heathens, we shall get a remarkable comment on this passage from Tertullian, who, in his treatise De Carne Christi, chaps. 37, 39, gives us a melancholy account of the height to which superstition and idolatry had arrived in his time among the Romans. "A child," says he, "from its very conception, was dedicated to the idols and demons they worshipped. While pregnant, the mother had her body swathed round with bandages, prepared with idolatrous rites. The embryo they conceived to be under the inspection of the goddess Alemona, who nourished it in the womb. Nona and Decima took care that it should be born in the ninth or tenth month. Partula adjusted every thing relative to the labor; and Lucina ushered it into the light. During the week preceding the birth a table was spread for Juno; and on the last day certain persons were called together to mark the moment on which the Parcae, or Fates, had fixed its destiny. The first step the child set on the earth was consecrated to the goddess Statina; and, finally, some of the hair was cut off, or the whole head shaven, and the hair offered to some god or goddess through some public or private motive of devotion." He adds that "no child among the heathens was born in a state of purity; and it is not to be wondered at," says he, "that demons possess them from their youth, seeing they were thus early dedicated to their service." In reference to this, he thinks, St. Paul speaks in the verse before us: The unbelieving husband is sanctified by the wife - else were your children unclean; but now are they holy; i.e. "As the parents were converted to the Christian faith, the child comes into the world without these impure and unhallowed rites; and is from its infancy consecrated to the true God."

Paul answers an objection: but the faithful is defiled by the company of the unfaithful. The apostle denies that, and proves that the faithful man with good conscience may use the vessel of his unfaithful wife, by this, that their children which are born of them are considered holy or legitimate (that is, contained within the promise): for it is said to all the faithful, I will be your God, and the God of your seed.

7:14 For the unbelieving husband hath, in many instances, been sanctified by the wife - Else your children would have been brought up heathens; whereas now they are Christians. As if he had said, Ye see the proof of it before your eyes.

Holiness extends to whatever is in relationship with the divine; it includes the idea of separation and opposition to what is profane and common; it expresses the idea of belonging to or being possessed by God.

In short, the difference between children of believers and children of non-believers; or; difference between children of Christians and children of non- Christians, i.e. pagan and holy. Clean and unclean.

Eph:2:11: Wherefore remember, that ye being in time past Gentiles in the flesh, who are called Uncircumcision by that which is called the Circumcision in the flesh made by hands; Eph:2:12: That at that time ye were without Christ, being aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world:

Eph:2:13: But now in Christ Jesus ye who sometimes were far off are made nigh by the blood of Christ.

A similar instance is the vision Peter had as to baptism of Cornelius where the Lord asked him not to consider unclean what He has deemed clean and thus called for the admission & baptism of the Gentiles to the church as well.

Peter tells of Christians as being ‘a royal priesthood, a holy nation’. ! Paul in Cor 7:14 tells that children born of Christian parents (even if one of the parent is Christian) are not unclean but holy. i.e. they are also part of the holy nation

In turn meaning that the children of unbelieving are not part of the holy but remain unclean or unholy

1Th:4:7: For God hath not called us unto uncleanness, but unto holiness.

Infants when moved by  God’s grace can receive  His Gift of faith.  Consider Luke 1:44, when Mary brought Jesus to St. Elizabeth and St. John the Baptist.   Elizabeth replied, "The infant in my womb leaped for joy…"   So, we cannot scientifically measure a person’s predisposition to receiving God’s saving Grace.

We must enter into God’s Kingdom the same way an infant enters or accepts it. 

John 14:6   "No one comes to the Father except through me."

Christ Reigns!!