After the church was established men and women went throughout the world preaching the gospel message. The book of Acts records a uniform message that was preached. Starting on the Day of Pentecost we find a foundation sermon delivered by the Apostle Peter. Peter preached about Jesus Christ and man's sins. Those who believed that Jesus was the Christ and were willing to repent and be baptized for the remission of their sins would be forgiven (see Acts 2:37-38). Every sermon preached after Peter's was a carbon copy of Peter's words. Whether the preacher was Peter, Philip, Paul, or Luke the message was the same. Those who heard the gospel preached, believed the message, confessed that Jesus was the Christ, repented of their sins, baptized for the remission of their sins, and purposed to live faithfully all the days of their lives were added to the church of Christ (Romans 16:16).
Preaching the same message of Jesus was very important. At Acts 15 we find that some were preaching additional things for salvation. The erring was saying that unless people were circumcised they could not be saved (see Acts 15:5). The church had a great issue with these false teachers.
The method of salvation had already been preached to thousands and the church was consequentially growing. To add something to the salvation equation that God did not was error. Today, many denominational bodies have added and subtracted from the original pattern of hear, believe, confess Christ, repent of sins, be baptized for the forgiveness of sins, and live faithfully. Nothing has changed in God's message yet man tries to change it. Some say that you do not have to be baptized to be saved and forgiven of sins. Others say that all you have to do is say the sinner's prayer to be saved. Such words are daring and great error (see 2 Peter 2:1, 10 and 2 John 9-11). The pattern, or Law, has been established by Christ and no man has the right to alter those words (see
John C Robertson