If I had a brother who had been murdered, what would you think of me if I...daily consorted with the assassin who drove the dagger into my brother's heart; surely I too must be an accomplice in the crime. Sin murdered Christ; will you be a friend to it? Sin pierced the heart of the Incarnate God; can you love it?"
Three texts in Revelation tell us who and what will be absent in heaven. In 21:4 we see that no tears of grief, no death or sorrow or pain will be present. In 21:8 we are assured that no one who is cowardly, lying, or unbelieving will be present, or murderers, or anything abominable, immoral, or idolatrous. And, as if to sum up, we are told in 21:27 that nothing unclean will be allowed to enter.
God has commanded us in his word, "You shall not murder" (Exodus 20:13). And He told us why. He said in Genesis 9:6, "Whoever sheds the blood of man, by man shall his blood be shed, for God made man in his own image." In other words, when you murder a human, you attack God who makes every human in his image.
Author: John Piper Source: Love Your Unborn Neighbor, Sermon: January 22, 2006