Why do Christians always say people (who have sinned) have gone to heaven when they have just died?

NO one knows whats in a persons heart, not even a Christian can judge the Heart,, so when you die, YOU will have been the one that decided where you go,,not me,,,,and when a person is dead I don't believe in talking bad about them, you may, but not me, I try to see the best in people, your comments don't reflect that belief..that is your choice, not mine