I hear claims that because there are stories of violence in the Bible that we should reject the claims of Christianity. This is a straw man argument; it ignores the actual manner in which Catholics understand and use the Bible. For us, the proper way of understanding all scripture is within the context of the teaching authority of the Catholic Church. This teaching authority comes to us from the Apostles who got it from Jesus.
An excellent resource for reading scripture in context is the Ignatius Press version of the DIDACHE BIBLE. Or, if one prefers, the CATECHISM OF THE CATHOLIC CHURCH (CCC) is free at the Vatican website. Please note that the CCC is heavily footnoted to the Bible, and that the DIDACHE BIBLE is a study Bible that uses the CCC for its commentary.
History demonstrates that humans are a violent species. Just read up on ancient cultures. In the region where the Hebrews lived there were religious groups that practiced all manner of sacrifices, including human and even infant. So common was it, that when asked to give up his only son, Abraham dutifully went off to do exactly that, trusting that God would fulfill his promise of descendants through this son even if he were to sacrifice him on the altar. We learn from the Church that this story from the Old Testament demonstrates the supernatural nature of Abraham’s faith in God.
Living with the deeply ingrained belief that sacrifices were essential to the atonement for sin, in a time when some cultures went so far as to throw infants into fires before idols in the hopes of a good crop or other necessity, the leap of understanding from human sacrifice to the sacrifice of a Ram was significant. It was a HUGE conceptual leap. We are taught by the Church that it showed Abraham and his descendants not to copy the human sacrifices of their neighbors.
Another example: God commanded the Hebrews to go to war and leave none alive, not even the livestock. We understand that in that time, humanity was violent and cruel. Genocide was a common practice, and to preserve the Hebrews and the ideas God was teaching them to comprehend, God had them do what was necessary to survive. Without their survival, the ideas they gave to the world would have been lost.
If YOU lived in a time when the ONLY way your children and extended family could survive was to be so powerful and violent that potential enemies left you alone, what would you do? The Hebrews, without great armies, without walled cities, were without any defense against being killed off. God said, attack and I shall help you; and with their tiny group of men they did as God commanded and, against ridiculous odds, succeeded and survived– would you not be rejoicing for having won the right to exist?
The Catholic Church teaches the validity of self defense. These stories serve to illustrate the extreme violence of the human race before Christ. This was how humans were, and the Hebrews, while carrying many concepts that were new, were still people of their time. The historical tales of the Old Testament illustrate where humanity goes when apart from Christ, demonstrates how God intervened and, because of the obedience and faith of Abraham, began the long process of forming the Hebrews into people from whom Jesus could come.
To further understand some of the ways that God changed the understanding of the Hebrews during the many years represented by the Old Testament, you might enjoy the book, THE GIFTS OF THE JEWS: HOW A TRIBE OF DESERT NOMADS CHANGED THE WAY EVERYONE THINKS AND FEELS by Thomas Cahill.