Imagine, for just a moment, a very evil man—a psychopath who ambushes unsuspecting people and murders them. He averages about one murder per week. Then he dies. Does God welcome him into heaven?
No one would answer “yes” to that question. Everyone believes that there are some sort of standards for gaining entrance in heaven, and someone who regularly commits murder doesn’t meet the standard. With them, the New Testament agrees: “Everyone who hates his brother is a murderer; and you know that no murderer has eternal life abiding in him” (1 John 3:15, emphasis added).
Now, let us imagine that, just before the man dies, he believes in Jesus and asks God to forgive him. All Christians would say that, because salvation is by grace through faith, God would welcome that man into heaven—as a sinner saved by grace. Jesus died for his sins, making such amazing grace possible.