The Old Testament is the part of the Bible dealing with the time before Jesus. Jews call it the "Tanakah".
The term "Old Testament,"1 or more properly "Old Covenant," is a Christian designation, reflecting the belief of the early Christian Church that the "new covenant" mentioned in Jer. 31:31-34 was fulfilled in Jesus and that the Christian scriptures set forth the "new covenant," just as the Jewish scriptures set forth the "old covenant" [1]
Many sections of the Old Testament show a God similar to what one would expect a primitive pastorial community to believe in. God frequently appears limited, neither omniscient nor omnipotent. Just one example is the Bronze Age Tower of Babel which could have become a serious threat to him. Genesis 11.[2]
The God of the Old Testament is a vindictive God and in no way Omnibenevolent. For example, an innocent baby was killed to punish David and his mistress for committing adultery, among others. Human sacrifice was rare but happened. Isaac was saved at the last moment but would have been traumatised the way the victims of fake executions are traumatisded. The virgin daughter of Jephthah wasn't so lucky. King Moab's eldest son was unlucky as well [3]. More on Human Sacrifice. Fortunately there is no reason to believe this is more than Mythology.