Our faulty idea of the God of the Old Testament, who seemingly orders the extermination of whole peoples, is indeed primitive and superstitious when placed beside the concept of the Father of Jesus who sends his son into the world as a helpless infant and then lets him die helpless before a mocking crowd. The God whom Jesus reveals is devoid of all violence and asks that we no longer do violence in God's name.
To offer just one example: In John's Gospel (8, 2-11), we see the story of the woman who has been caught in adultery. As John tells the story: A crowd of pious persons bring her to Jesus and tell him that they have caught her in the very act of committing adultery and that Moses (their primary interpreter of God's will) has ordered that for this offense, she needs to be put to death. Jesus, for his part, says nothing, instead he bends down and begins to write on the ground with his finger. Then he tells them: "Let the person among you without sin cast the first stone!" Jesus bends down and writes for a second time with his finger. Unbelievably, they get the message and lay down their stones and go away.
The key for interpretation of this story is Jesus' gesture of writing on the ground with his finger. Who writes with his finger? Who writes twice? God does, writing with his finger, twice! What God wrote are the Ten Commandments, and God had to write them twice because Moses "broke" them the first time. Coming down the mountain, carrying the tablets of the commandments, Moses caught the people in the very act of committing idolatry. Gripped in a fever of religious and moral fervor, Moses broke the tables of stone on the golden calf and on peoples' heads. Moses was the first person to break the commandments and he broke them physically, thinking violence needed to be done for God's cause. Then, having broken them, he needed to go up the mountain a second time and have them rewritten by God; but before rewriting them, God gave Moses a stern message: Don't stone people with the Commandments! Don't do violence in my name! The people who wanted to stone the woman caught in adultery understood Jesus' gesture. Their divine interpreter, Moses, had it wrong.
Too often we are still, in a variety of forms, stoning people with the Commandments, falsely believing that God wants this violence.