Colossians 2:6-7
Therefore, as you received Christ Jesus the Lord, so walk in him, rooted and built up in him and established in the faith, just as you were taught, abounding in thanksgiving.
Baptism is not exclusive to adults, to the learned, to the dedicated, or to the accountable. It is not limited to those who have made a decision for Christ. It is never restricted because it is God's saving Word, and His power to save is never inhibited.
A little child, even the tiny infant receives Christ through baptism. Little hands do not reach up into heaven. God's nail-marked hands reach down to the child. That little one’s immature voice is fluent only in the bawl of a newborn baby. He or she has nothing sweet to say, but sweet are the promises Christ speaks. "You were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God." (1 Cor. 6:11)
I recall the holy baptism of my dear granddaughter. The work was God's, not hers.
This was God's work, not that of the church, or her parents, nor her sponsors, nor by anything she fetched along. She came with nothing but her need, her sin, and her helplessness.
The delivery of life comes through Christ alone. Scripture can be understood rightly in no other way.
"Christ loved the church and gave Himself up for her to make her holy, cleansing her by the washing with water through the word." (Eph. 5:26)
Have you ever seen a baby clean up after itself? Babies have a regular habit of making a stinking mess. Likewise, born corrupt, every babe-in-arms has no way out of the soil of sin. The answer is Christ who cleanses through the Word in baptism.
Again: "He saved us through the washing of rebirth and renewal of the Holy Spirit, whom He poured out on us generously through Jesus Christ our Savior, so that, having been justified by His grace, we might become heirs having the hope of eternal life." (Titus 3:5-6)
Have you ever seen an infant free itself from a broken high chair or run from a dangerous animal? Likewise, saving from the devil's threats and this broken world is the Lord's rescue.
"He has rescued us from the dominion of darkness and brought us into the kingdom of the son He loves, in whom we have redemption, the forgiveness of sins." (Col. 2:11-12)
Christ has done this. There is nothing whatsoever in these texts that suggests salvation is teamwork. Baptism is neither our act of submission nor our act of worth. It is entirely God's doing. The child of God (infant or elderly) receives. That's it: God delivers and we receive.
We don't earn, merit, or deserve one good thing from God. Yet, through the grace of His Son, God gives the kingdom of heaven with one Word and one drop of water.
This is how one receives Christ. As a gift! Through no work of one's own!
Our granddaughter didn't lift a finger. She supplied exactly nothing. Her contribution added up to one comprehensive grand total of absolute zero.
Christ did it all. He loved her, He elected her. He lived for her and died for her. He conquered death for her. He created her. He sought her and planned for her. He supplied her life and limb, home, family, and health. And He did all of this for her without one iota of exertion or one grain of understanding from her.
Do not suppose, therefore, that the greatest Gift of all, the gift of the Holy Spirit, forgiveness, and eternal salvation will be hers only on consignment.
To deny infant baptism is to emasculate the very Gospel of Christ.
It places God into limbo waiting on events determined by the choices we make. Nothing could be more radically contrary to the very core of the Christian message. It basically makes God an observer rather than the Savior.
If you understand the absolute grace of Christ in baptism, then you will also understand the remainder of these short verses and how one walks in Christ as they grow older. It is by grace.
How is one built up and established in the faith? Not by making mighty efforts, wringing out of ourselves decisions to do better, or committing oneself to strict religious practice. No, it is by faith in Christ's goodness and depending utterly on Him.
How is one to abound in thanksgiving?
Never by turning a share of it back on oneself with congratulations for anything we have done. Ours is simply a life of thanks rendered to Christ alone for his endless love and goodwill.
That is the life our granddaughter was given. That's why the day of her water baptism in the Name of the Father and of the Son and of the Holy Spirit was the greatest day in her life (not just the greatest to up until then, but the greatest ever!). And that's why it was a sublime joy for all of us to share - because we are the baptized too.