Through no goodness or deserving of our own, God claims us for Himself, sets His seal of love upon us, and grants new hearts which cling to Him by faith. It isn’t because this child is cute enough, clever enough, or is sleeping enough that we place this sign of baptism upon him. No. We baptize him because God has promised that from everlasting to everlasting, His mercy shall be upon them that fear Him, and his righteousness unto their children’s children (Ps. 103:17).
A father turns in faith to God, and receives mercy through Jesus blood. He then stands as a representative for his household and lays hold of God’s covenant promise to show mercy to a thousand generations of them that love Him and keep His commandments (Ex. 20:6). And so, this child receives the sign of promised mercy, and also this seal of assurance that God is faithful to covenant keepers. And what does this covenant demand? What are the obligations which rest upon this child? He’s called to believe that Jesus is the Christ (1 Jn. 5:1). As that old hymn wonderfully puts it:
Nothing in my hand I bring, simply to Thy cross I cling.
Naked come to thee for dress, helpless look to thee for grace.
So welcome, covenant child, to Jesus Christ.