It would make sense to baptize babies if they were born sinful. The problem with this idea is that the bible does not teach that babies are born sinful, nor does it teach infant baptism. In Ezekiel 18:4, God says: “behold, all souls are Mine; the soul of the father as well as the soul of the son is Mine; the soul who sins shall die.” Further in the chapter, He says in verse 20, “the soul who sins shall die. The son shall not bear the guilt of the father, nor the father bear the guilt of the son. The righteousness of the righteous shall be upon himself, and the wickedness of the wicked shall be upon himself.” Do we believe this? If we do, then we accept that one cannot be born sinful. Sin comes upon one who acts in wickedness; infants and children alike cannot commit wickedness nor are they accountable for their actions. Acts 8:26-39 is a good text that establishes that there is an age threshold that one must reach before they should be baptized. Notice in the text, that Philip is teaching an Ethiopian man, who, after understanding what Philip taught about Jesus, asked him “What hinders me from being baptized?” (verse 36). Look what happens next: “Then Philip said, ‘If you believe with all your heart, you may.’ And he answered and said, ‘I believe that Jesus Christ is the Son of God.’ So he commanded the chariot to stand still. And both Philip and the eunuch went down into the water, and he baptized him” (verses 37-38). What was conditional about whether one is ready for baptism or not? Philip said “if you believe with all your heart, you may.” This is the condition. This is the condition that infants and children cannot fulfill. They are not yet capable of such a decision. Many infants are baptized today, but it is adults who make that decision for them, breaking the conditions of baptism and nullifying the act. So then, we understand from the scriptures, that before one should be baptized, one must commit sin, come to a knowledge of their sin, come to a knowledge of their Savior, and believe in His power to saved them. Then and only then, is one scripturally ready to be baptized. Of course, there is more to the story, as scriptures like Romans 10:9 and Acts 2:38 reveal more conditions before one should be baptized, such as a confession with the mouth and repentance of sins. Infants cannot confess with their mouths, nor repent of their sins (for there is nothing to repent of), nor believe with all their heart that Jesus is the Son of God, nor make the choice for themselves to be immersed in a burial of water putting sin to death. How could they put sin to death if sin has yet to come alive in their life? (Romans 7:9).
Why do you say that only adults should be baptized, wouldn’t it be logical to baptize babies since we are born sinful?