The Meaning of Baptism in Acts

How are we to take the baptisms in the book of Acts? Should draw our doctrine and practices of baptism from the book of Acts? It seems that Luke has a fairly narrow purpose for writing the book of Acts. He records the Apostles witness of Jesus being the Christ. Baptisms in Acts serve as a testimony that the gospel of grace through Christ is should preached and received among people from Jerusalem, to Judea and Samaria, and to the ends of the earth. Thus, Baptisms in Acts are the testimony that none are excluded from God's grace in Jesus Christ.