We are all sinners. If you want to make heaven,you can ask God for mercy. Jesus Christ said in Matthew 7:21 - Not every one that saith unto me, Lord, Lord, shall enter into the kingdom of heaven; but he that doeth the will of my Father which is in heaven.
Are Christians not the ones who call Jesus Lord?.So,this means that it is not all Christians(who are the ones who call Jesus Lord)that will make the Kingdom of heaven but those who do the will of the father in heaven.
How can you be sure to make heaven? The bible says Matthew 7:7-Ask, and it shall be given you
We can ask for the grace to do the will of the father in heaven and make heaven.
Let's ask-In Jesus name- Father, thank you for your loving kindness and tender mercies. Please grant us the grace to do your will. Amen