Since a child does not always reflect on his own misdeeds, I'll use a adult. If an adult stole a pocket book when visiting his neighbor, and the neighbor found out, he may forgive the adult. If he does, that is not the end because the adult did not ask for repentance but just keep the apology and walked off with it. When you have any type of relationship with someone there is a give and take. So, not only would it be mindful for the adult to ask for forgiveness, he also needs to forgive himself. Repentance means change one's actions to reflect the forgiveness made by oneself and from others. It's a change of heart; so, they do relate to each other.
31 Get rid of all bitterness, rage and anger, brawling and slander, along with every form of malice. 32 Be kind and compassionate to one another, forgiving each other, just as in Christ God forgave you. Ephesians 4:31-32
Once the adult asks forgiveness and god forgives them, then they repent by changing their ways and being kind and compassionate towards other people.
Repent, then, of this evil plan of yours, and pray to the Lord that he will forgive you for thinking such a thing as this. (Acts 8:22)
But if that person doesn't ask forgiveness, then, of course by default
your scriptures would be correct. However, since that murderer is changing his life (repenting), the verses you quoted does not match the benefit the murderer receives for asking repentance and receiving forgiveness with change of heart and mind.
9 If we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness. 1 John 1:9
So, once you repent, your sins (99% including murder) will be forgiven. By christ's blood that murderer heart is purified and free for him to be kind and compassionate.
By saying that god does not hear a murderer's prayers (unless, again I ask if you can clarify it) to me is saying that murder cannot ask for forgiveness thereby your verses would be correct and mine rebutted.
Now if we were using two separate sources, I can see it. We are not. So, I am addressing your scriptures. How am I interpreting the scriptures "wrong" and why are 98% percent of sins forgiven when scripture says all but one?
25 “I, even I, am he who blots out your transgressions, for my own sake, and remembers your sins no more. 26 Review the past for me, let us argue the matter together; state the case for your innocence. Isaiah 43:25-26
I'm giving you all positive verses because what you are saying is that our deeds seal a christian's fate not the grace of god and sacrifice of his son.
Repent, then, and turn to God, so that he will forgive your sins. (Acts 3:19)
What more can I say unless you address these specific verses and explain how I am wrong.