If we look at Scriptures relating to both ideas, we trust it will provide the answer.
What does the Bible say about baby dedication?
Exodus 13:2, "Sanctify unto me all the firstborn," and verse 18, "the firstborn males shall be the Lord's." The firstborn were especially dedicated to God and his service. Mary and Joseph took Jesus to Jerusalem for this purpose, Luke 2:22, 23, "…they brought him to Jerusalem, to present him to the Lord; (As it is written in the law…, Every male that opens the womb shall be called holy to the Lord;)
1 Samuel 1:11, Hannah dedicated Samuel to the Lord even before he was born, in thankfulness that she could have a child, "And she vowed a vow, and said, O LORD…if thou will…give unto thine handmaid a man child, then I will give him unto the LORD all the days of his life."
Parents who dedicate their children to the Lord are saying that they are dedicating to Him the best they have – their children. This desire encompasses giving their children an upbringing in which they will learn about God and Jesus. Child dedication is wise and noble. The parents will nurture good character traits of honesty, kindness, and love in the children. The children will be taught to appreciate and be thankful for God's blessings in their lives.
What does the Bible (New Testament) say about baptism?
1) The Greek word "baptizmo" from which we get "baptism" means to be covered in water. If this is done in a ceremony, it is only a symbol of the real baptism which is to be fully immersed in doing God's will after repenting of sin.
2) Jesus explained what baptism means when he said, "If any man will come after me, let him deny himself, and take up his cross, and follow me," Matthew 16:24. His followers gave up their own will to live a sacrificial life, as Jesus did.
3) Paul says the same thing about baptism in Romans 6:3, 4, "Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death? … so we…should walk in newness of life. Baptism means that the individual dedicates his entire life – all he has, hopes for, and all he is – to doing God's will, not his own will. It is the death of his human will.
Is baby baptism found in the Bible? No. Baptisms in the New Testament are adult baptisms. Jesus was dedicated by his parents as a baby, according to the Hebrew law, but was not baptized by John the Baptist until he was thirty years old. Luke 3:21 "…Jesus also being baptized, and praying, the heaven was opened, (verse 23), "…Jesus himself began to be about thirty years of age…"
Is there a relationship between baby baptism and salvation? No. Salvation is based on the recognition that the person is a sinner and that Jesus died for his sins. Upon these truths, the sinner accepts Jesus as his Savior and then dedicates his life to doing God’s will.