Okay. We can get mixed up on words a little once in a while. Christianity is the only religion where salvation itself is given by God as a simple and pure gift, if the person accepts it. All other religions that offer salvation have the individual working for it a bit at least.
I find that to be a flaw. A murder, rapist, or mass killer could be a Christian. After killing thousands of people, he/she should still be granted access to heaven where everything is great?
There is rumor, and strong evidence here and there, that Hitler made it to Argentina after WWII, and died there in his 90s.
If Hitler turned to Jesus in repentance for his crimes, and accepted that God would forgive him because of the sacrifice Jesus did on the cross, even Hitler would be saved.
Which is obviously a flaw. People like that should not be saved just because he believes in the sacrifice of Jesus. If you believe that Hitler should belong in heaven, then I don't know why I'm even having this conversation with you.
The Lord created all of humanity. He loves us all beyond anything we can imagine. The best example is a parent loving his or her child, but it's so far beyond that. He made us in the womb. Psalm 139:13
He wants EVERYONE saved, because He loves us so much. That's why Jesus dying on the cross is such a big deal. He died so anyone can be saved from death. Plus Hitler was demonically oppressed. And though he did what he did (and shouldn't have), he was certainly egged on and led down the wrong path.
If he continued to kill, he would not be Christian. Once you get born again, you'd ask to be filled with the Holy Spirit, and it would change your heart of stone, to a flesh heart, figuratively. You would then, be convicted (have a conscience) telling you it's wrong, and would either follow Jesus's teachings and start getting away from all sin, or fall away and not be Christian (saved) anymore. Those who fall away from the teachings can continue to call themselves Christian and sin, but Jesus will not save them.
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. 22 Many will say to me in that day, Lord, Lord, have we not prophesied in thy name? and in thy name have cast out devils? and in thy name done many wonderful works? 23 And then will I profess unto them, I never knew you: depart from me, ye that work iniquity.
From what you've said though, he can kill as much as he wants. But if he wholeheartedly believes that the lord is the true savior, then he will be saved.
