The answer is simple: "Believe on the Lord Jesus Christ, and you shall be saved..." (Acts 16:31). But the problem is that the sinner does not want to be saved. That is why the Lord Jesus Christ can say to any one of us: "And you will not come to me, that you might have life" (John 5:40); and the "life" here is life eternal, i.e. the life of God; or it can be said, the "new life" that the sinner begins in Christ Jesus when he has "repentance toward God, and faith toward our Lord Jesus Christ" (Acts 20:21). This is proven every day that sinners, if left to themselves, do not want to be saved, because I am sure that it is testified to multitudes of the"salvation through faith which is in Christ Jesus" (2 Timothy 3:15), and we don't see sinners falling over each other to get to Christ to be saved from their sins.
The question is, Why? Because the sinner is in love with sin; and it can even be said that sin is their "first love". Note what the Lord Jesus says: "Light is come into the world, and men loved darkness rather than light, because their deeds were evil. For every one that does evil hates the light, neither comes to the light, lest his deeds should be reproved" (John 3:19,20). That's why the sinner without salvation "add sin to sin" (Isaiah 30:1); "for there is not a just man upon earth, that does good, and sins not" (Ecclesiastes 7:20). Know one thing, my dear reader, that according to the Bible, if you are without the Lord Jesus Christ in your life for not having received Him as your Savior, it matters not how moral or religious you are, it is still sin in the eyes of God because Christ does not "dwell in your heart by faith" (Ephesians 3:17).
Now, why do you need to be saved? Because if you, my dear friend, are without the Lord Jesus Christ in your life, and you die in that condition; or if you are in that condition when He returns again, be sure of this: You will have to pay for your sins for all eternity in "the lake of fire" (Revelation 20:15), which is "everlasting punishment" (Matthew 25:46); for all the ones "that know not God, and obey not the gospel of our Lord Jesus Christ,...shall be punished with everlasting destruction" (2 Thessalonians 1:8,9). Those are the consequences of unforgiven sin! This is true of every one that has not received the Lord Jesus Christ as their Savior.
But "this is a faithful saying, and worthy of all acceptation, that Christ Jesus came into the world to save sinners" (1 Timothy 1:15), because He came "to seek and to save that which was lost" (Luke 19:10); and you are lost if you have not believed in Christ for your salvation. Nevertheless, at this moment the Lord Jesus Christ is presented to you so that you may see that only in Him is there salvation: "Look to me, and be you saved..." (Isaiah 45:22); or as He says in John 6:40 - "Every one that sees the Son, and believes on him, may have everlasting life", and He "will raise him up at the last day". What a precious promise is this! Hallelujah!!!
The first reason why you have to believe on the Lord Jesus Christ to be saved is because He is the only one who died for sinners: There is no other! for "neither is there salvation in any other: for there is none other name under heaven given among men, whereby we must be saved" (Acts 4;12). On the Cross at Calvary, Christ Jesus was given as a ransom and as a substitute in the place of sinners, in that "God demonstrated his love toward us, in that, while we were yet sinners, Christ died for us" (Romans 5:8); or for me, can every one that truly believes in Him say "in full assurance of faith" (Hebrews 10:22)! Amen.
The second reason why you have to believe on the Lord Jesus Christ to be saved is because, not only is He the only one who died for sinners, but also He is the only one who was raised from the dead to put them right with God; "for if, when we were enemies, we were reconciled to God by the death of his Son, much more, being reconciled, we shall be saved by his life" (Romans 5:10). In other words, the guarantee that the atoning Death of Christ is effectual for the salvation of the repentant sinner that believes in Him, is because He was resurrected from the dead, "who was delivered for our offences, and was raised again for our justification" (4:25). This means that God not only forgives our sins "by the death of his Son", but He also justifies us, i.e. declares us righteous by faith in Him; and His bodily Resurrection makes this certain; for "if you shall confess with your mouth the Lord Jesus, and shall believe in your heart that God has raised Him from the dead, you shall be saved. For with the heart man believes into righteousness; and with the mouth confession is made into salvation" (Romans 10:8,9).
The third reason why you have to believe on the Lord Jesus Christ to be saved is because, not only is He the only one who died for sinners and resurrected for their justification, but also He is the only one who intercedes for every one that comes to God for salvation; "wherefore He is able also to save them to the uttermost that come to God by Him, seeing He ever lives to make intercession for them" (Hebrews 7:25). He is the only "mediator between God and men" (1 Timothy 2:5); therefore, in order to be saved, the sinner has to come to God by, through, and in His Son, as Christ Himself says: "I am the way, the truth, and the life: no one comes to the Father, but through me" (John 14:6). Try to go in any other way, either by any other person, or any other means, and God will reject you! But in the Lord Jesus, you can rest assured that God will accept you, for Christ's sake. Amen!!!
ask again: "What must I do to be saved?" I tell you as the apostle Paul
told the Philippian jailor in Acts 16:31 - "Believe on the Lord
Christ, and you shall be saved...". But I ask you: Do you truly
to be saved? If you say Yes!, well then, come to Christ Jesus by faith,
believing that He died for you on the Cross, shedding His Blood for the
forgiveness of all your sins; also by faith look to the empty Tomb from
which He rose from the dead; and furthermore, by the eye of faith look
to Him as He speaks to the Father for you with the guarantee that you "shall
be saved in the LORD with an everlasting salvation: you shall not be
nor confounded world without end" (Isaiah 45:17). The promise is: "And
him that comes to me I will in no way cast out" (John 6:37).