What Must I Do?
First and foremost, you must put your trust in Jesus PLUS NOTHING. One of the clearest verses in the Bible on this topic is Acts 16:31. Right before this, in verse 30, a man (the Philippian jailer) asks the Apostle Paul and Silas, Paul’s partner, “sirs, what must I do to be saved?” And they respond “believe on the Lord Jesus Christ and thou shalt be saved, and thy house.” This does indeed sound simple, because it is (2 Corinthians 11:3). Jesus did the hard work so we wouldn’t have to, and He finished it (Hebrews 1:3, John 19:30). By the way the “and thy house” portion of this verse serves to show us that the offer of salvation is open to anyone who would believe.
Here is an analogy that may fit. When I use computer software that has been written by someone with a lot of expertise, who has put a great deal of thought into it and made it very orderly, it is usually relatively easy for me to use. It is intuitive. It makes sense, I understand how to use it. In contrast, when software is poorly and more carelessly designed by someone who is less competent, it is more likely to be buggy, unintuitive, difficult to use, unstable, etc. Jesus is an expert in all things (except for making mistakes of any kind), among them is saving people and giving them eternal life (Hebrews 1:3). He has done the hard work, which requires the expert, and has made it very simple and clear for us; the non-experts.
So back to the question of “what must I do?” What you must do is to believe on the Lord Jesus Christ. What does this mean? The Greek word for “believe” is phonetically rendered as “pisteo.” This means to fully rely upon; to commit one’s trust to. We often hear of “repenting” or “repentance” as well, in regards to the salvation that Jesus gives. What does all of this mean? Actually believing on Jesus and repenting are a one-in-the-same event. The Greek words used in the New Testament (of the Bible) that are rendered as “repent” in English, in 1611, when the King James Bible was completed, mean to change your mind about something. If in one moment I have never believed; fully relied on Jesus to save me from my sinful state, and then in the next minute I do believe; fully rely on Jesus to save me from my sinful state, I have obviously changed my mind; I have repented. In repenting, I have also believed; my belief IS that repentance. When one does this, Jesus saves them (John 3:16, 6:47). There are no works of the sinner involved in this (Ephesians 2:8-9). Jesus makes this even clearer in this passage:
Joh 6:28 Then said they unto him, What shall we do, that we might work the works of God?
Joh 6:29 Jesus answered and said unto them, This is the work of God, that ye believe on him whom he hath sent.
They ask what work they might do, Jesus makes it clear that there is no work that they can do for salvation. He was yet to do the work for them, and of course now, He has completed that work (1 Corinthians 15:1-4).
One may ask now about how a Christian should live. A Christian should be striving, by the Grace of God (who now dwells in him or her [Ephesians 1:13]), to be living his or her life fully devoted to Jesus. This is called discipleship. It is THE BEST way to live, for myriad reasons. Believers are blessed/rewarded for obedience in this life and the next. The believer is also chastised for disobedience in this life (sin has consequences), and potentially loses blessing/reward in the next life. However the believer is NEVER damned; salvation is irrevocable (Romans 11:29). True discipleship cannot happen until there is salvation, which is a free gift (Romans 5:16-18), which will never be taken away from one whom Jesus gives it to (Romans 11:29, John 3:16, 6:47, etc.) when they believe on Him (Ephesians 1:13). Please see Angles and Aspects of Salvation, and other writings on this site for more on both salvation and discipleship. Please feel free to contact me if you have questions. I would love to hear from you.
God bless you.