Jesus Christ died for your sins and rose again.
Believe the gospel, and you will be saved.
"Moreover, brethren, I declare to you the gospel which I preached to you, which also you received and in which you stand, by which also you are saved, if you hold fast that word which I preached to you—unless you believed in vain. For I delivered to you first of all that which I also received: that Christ died for our sins according to the Scriptures, and that He was buried, and that He rose again the third day according to the Scriptures." (1 Cor. 15:1-4)
"For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him." 2 Cor. 5:21
Jesus paid for all of your sins. Trust & believe He did this for you, and He will give you the free gift of eternal life. God made it so simple to be saved. He even warns against those who would corrupt the simplicity of it by preaching a different Christ or bringing a different spirit or different gospel. (See 2 Cor. 11:3-4 and Gal. 1:6-12)
Therefore I said to you that you will die in your sins; for if you do not believe that I am He, you will die in your sins. (John 8:24)
Then he called for a light, ran in, and fell down trembling before Paul and Silas. And he brought them out and said, “Sirs, what must I do to be saved?” So they said, “Believe on the Lord Jesus Christ, and you will be saved, you and your household.” (Acts 16:29-31)
For since, in the wisdom of God, the world through wisdom did not know God, it pleased God through the foolishness of the message preached to save those who believe. For Jews request a sign, and Greeks seek after wisdom; but we preach Christ crucified, to the Jews a stumbling block and to the Greeks foolishness, (1 Cor. 1:21-23)
Common questions
Q. Do I have to pray a special prayer to be saved?
A. No. You can pray if you like, but the prayer itself is not what saves you. You are saved by faith. Faith recognizes that you are a sinner in need of a Savior, that any and all sin deserves the death penalty, and that Jesus Christ, the Son of God, paid this penalty for you when He gave His life for you on the cross and then rose again from the dead. When you believe this, you are saved.
Q. Do I have to get baptized in water to be saved?
A. In John 5:24, Jesus said “Most assuredly, I say to you, he who hears My word and believes in Him who sent Me has everlasting life, and shall not come into judgment, but has passed from death into life." Water baptism is an illustration of passing from death into life. It is for Christians, i.e., those who are already saved. It does not save you, but after you are saved you are commanded to become baptized as a testament that you have died to the old (self & sin) and have been born again into the new life of Christ. (Rom. 6:3-14, 2 Cor. 5:17) Unsaved people have not yet experienced the new life of Christ, so baptism is not a testimony they can offer.
Q. Do I have to "confess with my mouth" to be saved?
A. Many people use Romans 10:9-10 to teach that salvation comes by faith plus confessing with your mouth that Jesus is Lord. To be understood, these verses need to be read in the context of the entire chapter and book of Romans. Here is a detailed study (.pdf link) that shows what this passage means in context. Romans 10:9-10 does NOT teach what individual folks must do to become saved.
Q. Do I have to confess my sins to be saved?
A. No. Salvation is by grace through faith. It does not come through anything you do. "For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, not of works, lest anyone should boast." (Eph. 2:8-9) "But they have not all obeyed the gospel. For Isaiah says, “Lord, who has believed our report?” So then faith comes by hearing, and hearing by the word of God." (Rom. 10:16-17) To understand confession of sins for a believer, I recommend Pastor Tom Cucuzza's teaching series on the book of 1st John (YouTube playlist of the sermons). If you prefer his written notes, here is his commentary.
Q. So all I have to do is just believe and I'll go to heaven?
A. If what you believe is that Jesus Christ was crucified to pay the death penalty you owe for your sins, then yes. Let's look at what it means to believe. It comes from the Greek word pisteuo which is to be persuaded, to have faith in, to trust in. If you are persuaded that Jesus Christ died in your place for your sin, was buried in death, and resurrected again to life, then on the authority of Scripture we can declare that you have become born again.
Q. Can you explain why I need to be saved?
A. ALL have sinned. God loves you and hates your sin, because it separates you from Him. He is perfect, and only perfect, sinless people can enter heaven and live forever. This is why God sent His perfect, sinless Son Jesus Christ to pay the debt you owe so you can be free and receive eternal life. When you trust & believe He died on the cross for you, He takes your sin upon Himself and gives you His perfection. You become born again of the Spirit. When God the Father looks at those who trust in Christ as Savior, He sees the righteousness of Christ instead of your sin. Your sin debt has been paid. This is called being justified freely by His grace.
Recommended teaching:
"Then he called for a light, and sprang in, and came trembling, and fell down before Paul and Silas, And brought them out, and said, Sirs, what must I do to be saved? And they said, Believe on the Lord Jesus Christ, and thou shalt be saved, and thy house." Acts 16:29-31