One thing that every human being which God our father has created is that we all have conscience which go far in telling us when we are doing good or bad.
It stands the chance to correct our path if only we give it listening ear. Anything we are doing be it something which is right or bad ,there is this inner being that always tell us if we are doing things right or in a bad way.
Same way it it applicable to securing heaven as our hope , when we are seen as people who keeps doing good and doing the will of our father who have sent here on earth. We will found that within and inside of us, that we have done and deserve the blessings of God from above.
So we can only be sure when we keep abiding to the commandments of God and consistently abiding to the teachings of our father in heaven.
Amen