Heidelberg Catechism · 1563

Q74. Should infants, too, be baptized?

Yes. Infants as well as adults belong to God's covenant and congregation. Through Christ's blood the redemption from sin and the Holy Spirit, who works faith, are promised to them no less than to adults. Therefore, by baptism, as sign of the covenant, they must be grafted into the Christian church and distinguished from the children of unbelievers. This was done in the old covenant by circumcision, in place of which baptism was instituted in the new covenant.
Answer · Heidelberg Catechism

Scripture proofs

  1. [1]
    Genesis 17:7

    And I will establish my covenant between me and thee and thy seed after thee in their generations for an everlasting covenant, to be a God unto thee, and to thy seed after thee.

    Matthew 19:14

    But Jesus said, Suffer little children, and forbid them not, to come unto me: for of such is the kingdom of heaven.

  2. [2]
    Psalms 22:11

    Be not far from me; for trouble is near; for there is none to help.

    Isaiah 44:1-3

    Yet now hear, O Jacob my servant; and Israel, whom I have chosen: 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. For I will pour water upon him that is thirsty, and floods upon the dry ground: I will pour my spirit upon thy seed, and my blessing upon thine offspring:

    Acts 2:38-39

    Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost. For the promise is unto you, and to your children, and to all that are afar off, even as many as the Lord our God shall call.

    Acts 16:31

    And they said, Believe on the Lord Jesus Christ, and thou shalt be saved, and thy house.

  3. [3]
    Acts 10:47

    Can any man forbid water, that these should not be baptized, which have received the Holy Ghost as well as we?

    1 Corinthians 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.

  4. [4]
    Genesis 17:9-14

    And God said unto Abraham, Thou shalt keep my covenant therefore, thou, and thy seed after thee in their generations. This is my covenant, which ye shall keep, between me and you and thy seed after thee; Every man child among you shall be circumcised. And ye shall circumcise the flesh of your foreskin; and it shall be a token of the covenant betwixt me and you. …

  5. [5]
    Colossians 2:11-13

    In whom also ye are circumcised with the circumcision made without hands, in putting off the body of the sins of the flesh by the circumcision of Christ: Buried with him in baptism, wherein also ye are risen with him through the faith of the operation of God, who hath raised him from the dead. And you, being dead in your sins and the uncircumcision of your flesh, hath he quickened together with him, having forgiven you all trespasses;

Proof texts as given in the original; verse text from the King James Version.