Modern church growth experts would tell you this cannot be done. But God did it. These verses present us with five marks of a church. They are five actions of which members of a church should always be a part. The Bible knows nothing of an unbaptized Christian.
Baptism serves as the rite of initiation into the church.
There are a number of different types of baptism described in the Bible. Devotion to the Apostles Teaching. The Apostles teaching would have been taken both from the Old Testament Scriptures as well as from the teachings of Jesus. Peter elsewhere exhorts believers to feed upon the pure milk of the Word. Babies need food if they are to grow.