The Old Testament that you quote was written by old Jewish men that strove to control the masses. The New Testament says just the opposite regarding the 'stoning' of sinners. From John: "He that is without sin among you, let him first cast a stone at her." Jesus Christ prevented the stoning death of a known adulterer.
From Wiki:
A group of scribes and Pharisees confronts Jesus, interrupting his teaching session. They bring in a woman, accusing her of committing adultery, claiming she was caught in the very act. They ask Jesus whether the punishment for someone like her should be stoning, as prescribed by Mosaic Law.[2] Jesus first ignores the interruption and writes on the ground as though he does not hear them. But when the woman's accusers continue their challenge, he states that the one who is without sin is the one who should cast the first stone. The accusers and congregants depart, leaving Jesus alone with the woman. Jesus asks the woman if anyone has condemned her. She answers that no one has condemned her. Jesus says that he, too, does not condemn her, and tells her to go and sin no more.
So, unless you follow the Old Testament as a member of the Jewish faith, the New Testament has no reference whatsoever to the 'killing of infidels' and if you still believe it does, I would like to see that passage from one of the gospels in the New Testament to prove it.
