Why do we baptize infants?

1. Jesus commands it. (Disciple all nations, baptizing and teaching (Mat28:18-20).
2. God promises to give us the Holy Spirit, who works faith in us, in Baptism (Acts 2:38).
3. God says, "The promise is for you and your children..." (Acts 2:39).
4. The actor in baptism is God. He forgives, cleanses us and adopts us as His children. Baptizing an infant highlights the fact that it is nothing that I do, nothing within me that brings about salvation, but that it all comes from God. (Eph 2:8)
5. Babies are born sinful (Ps 51:5), so they need the forgiveness and adoption of Baptism.
6. "Baptism now saves you" (1 Pet 3:21).
7. The Bible records the baptism of entire families, which would include extended family and any servants and their families. To assume that none of these had small children is a stretch (Acts 16:15 etc)
8. Why not? Baptism and Faith are gifts of God to those whom He would call. Who are we to hold them back? We are commanded to baptize, so we do, and the Church has for millennia.