--the bible is the source of God's truth, not those who claim to be Christians.
Wrong. The Bible only tells us of the Truth. It is
Jesus who is the
source of the Truth. John 14:6: Jesus replied, “I am the way, and the truth, and the life."
In any event, those Christians who practice infant baptism--who are the vast majority of Christians--get that from scripture. The Bible tells us that whole families--which would have included children--were baptized in the early church. Acts 16:33-34: "At that hour of the night the jailer took them and washed their wounds; then immediately
he and all his family were baptized. The jailer brought them into his house and set a meal before them; he was filled with joy because he had come to believe in God—
he and his whole family." Likewise Peter said "Repent and be baptized,
every one of you, in the name of Jesus Christ for the forgiveness of your sins. And you will receive the gift of the Holy Spirit. The promise is for
you and your children and for all who are far off—for all whom the Lord our God will call." Acts 3:38-39.
Jesus made belief a prerequisite to baptism in Mk 16:16. Since infants do not have the mental ability, cognitive skills to have a biblical belief they are not candidates for baptism.
If Mark 16:16 said "he that first believes and then is baptized" you might have a point. However, as written it does not make belief a prerequisite to baptism.
The purpose of baptism is for the remission of sin Acts 2:38. Infants are born without sin therefore again, they are not candidates for baptism.
Infants cannot knowingly sin, but they are born with a sinful nature. Psalm 51:5: "Behold, I was brought forth in iniquity, and in sin did my mother conceive me." Psalm 58:3 "The wicked are estranged from the womb; they go astray from birth, speaking lies."
Now, you are certainly welcome to your interpretation of scripture. However, I and the majority of Christians disagree with your interpretation.