Genesis 4:9 And the Lord said unto Cain, where is Abel thy brother? and he said, I know not: am I my brother's keeper?
Cain was not only lying before God, but he also had a very wrong attitude. Yes he knew where his brother was, and yes he was his brother's keeper.
Unfortunately some Christians have this same attitude. They know that their brother is dead spiritually, yet they say to God that he is not their responsibility, but they are absolutely wrong. Yes we are our brother's keepers.
Won't you please come out here in the streets and help us to rescue our brothers, who are dead in trespasses and sin, by telling them about Jesus the giver of life.