If that prayer is answered by God, anything else answered is gravy. If that prayer is not answered by God, no other answer (really, nothing else) matters.
The good news is that this is the one prayer certain to get answered if asked.
The underlying basis for answering this prayer is already laid, demonstrably, tangibly in history. He who knew no sin became sin for us, and died in our sin that we might be forgiven. This basis for forgiveness is proven, because having taken our sin and incurring our death, Jesus rose victorious over them.
If we say that we have no sin, we are deceiving ourselves and the truth is not in us. If we confess our sins, He is faithful and righteous to forgive us our sins and to cleanse us from all unrighteousness. If we say that we have not sinned, we make Him a liar and His word is not in us. My little children, I am writing these things to you so that you may not sin. And if anyone sins, we have an Advocate with the Father, Jesus Christ the righteous; and He Himself is the propitiation for our sins; and not for ours only, but also for those of the whole world. I John 1:8-2:2 NASB