You can’t go to Heaven if you have unforgiveness in your heart. Say this prayer to be set free from unforgiveness. If you harbor unforgiveness you won’t be effective in Spiritual Warfare.
“Father, in Christ Jesus’ Name, I lay down at Your feet all present and past unforgiveness, anger, bitterness, or resentment, directed at (say the name or names). I repent of it and renounce it all, and ask You to forgive me for it. I forgive and release them. I repent for anyone who was hurt by it, and ask for Your forgiveness for that also. I forgive and release myself of all unforgiveness, anger, resentment and bitterness also. I renounce this and all past sin, and ask You to forgive me, Lord Jesus Christ. I ask all these things in Your Holy Name, Amen.”
You may have to say this prayer a thousand times in your life but it is a must you say it and start to mean it or you can’t go to Heaven. I would rather say this prayer a million times than to burn forever in hell.