Heaven

For God so loved the world, that he gave his only begotten Son, 
that whosoever believeth in him should not perish, 
but have everlasting life.                                                      John 3:16
God wants you to be 100% sure that when you die you will go to heaven. That's why the Bible says, "These things have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life." I John 5:13

Admit your a Sinner

WHY CAN’T WE GO TO HEAVEN? Because we are all sinners! Sin is when we break any of God’s commandments. No one other than Jesus Christ could ever lead a life without one single sin. Nobody but Jesus Christ is that righteous. The Bible tells us,
“...There is none righteous, no, not one...For all have sinned, and come short of the glory of God;” (Romans 3:10, 23)
If you claim to be righteous, you are only deceiving yourself and making God a liar. The Bible says, “If we say that we have no sin, we deceive ourselves, and the truth is not in us...If we say that we have not sinned, we make him a liar...” (1 John 1:8, 10)
We must then conclude that in our natural state, God views us as lost sinners. No one is good enough to go to Heaven on their own merit. No matter how much good we do, we still come short.

Realize the punishment for sin

After a person dies their soul can go either Heaven or Hell. • The penalty for our sin is eternal death in a place called Hell. The Bible actually describes Hell as terrible:
a place of fire, brimstone, and torment that last forever. (see Revelation 20:10)
• The devil is going to Hell for sure, but unfortunately we all deserve Hell. Not only the real bad people deserve to go there, but even seemingly minor transgressions, such as lying, warrant this punishment from the perspective of a Holy God.
Revelation 21:8 "...all liars, shall have their part in the lake which burneth with fire and brimstone: which is the second death."  (see also Revelation 21:27)

The Gospel - The death, burial, and resurrection

The Good news is God does not desire for us to end up in Hell.
 "But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us." - Romans 5:8

• The Bible says Jesus Christ was the son of God. 
• Not only is he the son of God, he is God. God sent his son to this earth to take the punishment & penalty we deserve.
• Jesus Christ was born of the virgin Mary. He became a man.
• He lived a sinless & perfect life, a life none of us could live.
• The Bible said he performed many miracles, proving he was the son of God. Not only that, HE SAID he was the son of God. But the Jews rejected the Lord Jesus Christ: arrested him, beat him, NAILED HIM TO A CROSS. He was whipped, spat upon, and shed his blood. Even though they killed the Lord Jesus Christ, he willingly went to the cross to take the penalty & punishment we deserve & when he was on the cross the Bible says he bare our sins in his own body on the tree. Every sin you’ve ever committed Jesus Christ paid for on the cross: past, present, and future. He didn't pay for just some sins, he PAID FOR ALL SINS. "He was buried, and that he rose again the third day according to the scriptures:" 1 Corinthians 15:4

Faith Plus Nothing Minus Nothing

If you died today and stood before God and asked, "Why should I let you into heaven?" In Matthew 7:22 Jesus said there would be people who call themselves Christian and call Jesus, "Lord," but there's a problem.
"Many will say to me in that day, Lord, Lord, have we not .... done many wonderful works. Yet, Ephesians 2:8-9 teaches salvation is "Not of works."                 
They claim to believe that Jesus was their Lord, but they don't believe simply by putting your faith in what Jesus already did for us alone is enough. Why else would they bring up their works? • God sees all our righteousnesses are as filthy rags. (see Isaiah 64:6)
That's what they think going to get them into Heaven and it's very clear that they're not really trusting Christ alone; they're still trusting in themselves. (see also Romans 11:6)
Matthew 7:23 "And then will I profess unto them, I never knew you: depart from me, ye that work iniquity."
• Notice God said to them "I never knew you," not "I used to know you" They didn't lose their salvation they once had. Our assurance lies in recognizing that once God knows us, He knows us forever. It's once saved always saved. • Will you stop trusting your righteousness, and put all your faith in Jesus Christ and receive His righteousness? If you will call on Jesus Christ and put all your faith in Him, He will save you right now.
“That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved." "For whosoever shall call upon the name of the Lord shall be saved.” (Romans 10:9,13)

What should I pray?

There are no special words or prayer that will grant eternal life. We simply must confess Jesus and believe with all our heart. Below is a example prayer based on the scriptures mentioned above.

"Dear Jesus, I know that I have sinned, and I deserve to go to hell, but I believe that you died for me, was buried, and rose again. Please save me and give me eternal life. I’m only trusting in you alone, not my works. In Jesus’ name I pray. Amen."

Embrace the gift of eternal life that God offers you today. Trust in Jesus Christ and find the assurance that your place in Heaven.