In setting forth the commission, Jesus set forth five steps that lead to salvation - Matthew 28:19-20, Mark 16:16, and Luke 24:46-47.

To summarize, Jesus said...

1. The gospel was to be preached to lost men
2. They were to believe
3. They were to repent
4. They were to be baptized
5. They were then saved

The first gospel sermon is a fine illustration of this obedience... they heard and believed the gospel, were then told to repent and be baptized, and then were saved, being added to the church (Acts 2:14-41).

This pattern of gospel obedience must be maintained today!

The apostle Peter wrote, Through him you believed in God, who raised him from the dead and glorified him, and so your faith and hope are in God (1 Peter 1:21).

Likewise, the apostle Paul also shows what obeying the gospel obtains for us: Don't you know that when you offer yourselves to someone to obey him as slaves, you are slaves to the one whom you obey - whether you are slaves to sin, which leads to death, or to obedience, which leads to righteousness? But thanks be to God that, though you used to be slaves to sin, you wholeheartedly obeyed the form of teaching to which you were entrusted. You have been set free from sin and have become slaves to righteousness. (Romans 6:16-18).

Now, you can chart the course of their obedience by carefully studying the first section of Romans 6:3-6: they died to sin, were buried in baptism, and raised to walk in newness of life: Therefore, if anyone is in Christ, he is a new creation; the old has gone, the new has come (2 Corinthians 5:17).