How you can be 100% sure you are going to heaven
God's word says: "For all have sinned, and come short of the glory of God;" Romans 3:23
Sin separates us from God.
God's word says: "For the wages of sin is death..." Romans 6:23
This is a spiritual death which will separate the sinner from God in heaven to eternal hell.
God's word says: "But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us." Romans 5:8
Christ paid the penalty for our sins on the cross.
God's instructions: "I tell you, Nay: but, except ye repent, ye shall all likewise perish." Luke 13:3
Be willing to turn from your sins and desire the change God brings.
God's instructions: "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." Romans 10:9
Believe in your heart that Christ died and rose again. That is faith in God.
God's instructions: "For whosoever shall call upon the name of the Lord shall be saved." Romans 10:13
If you call upon the name of the Lord, He will save you from your sins. You must deal with your sin.
God's Promise: "...but the gift of God is eternal life through Jesus Christ our Lord." Romans 6:23
The only way you can be saved is by accepting His gift of eternal, Jesus Christ.
Confess and Pray: "Lord Jesus, I know that I am a sinner, and I am sorry for all my sins. I ask You to forgive me of all my sins. The best I know how I am receiving Jesus Christ as my Savior right now. In Jesus' name I pray. Amen."