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" 
The Old testament includes history, Mythology, laws (some of them barbaric) and other material.
The God of the Old Testament
Many sections of the Old Testament show a God similar to what one would expect a primitive pastoral 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. 
Human sacrifice was rare but happened. Isaac was saved at the last moment  but would have been traumatized the way the victims of fake executions are traumatised.  The virgin daughter of Jephthah wasn't so lucky.  King Moab's eldest son was unlucky as well  . Fortunately there is no reason to believe this is more than Mythology.
Later in the Old Testament
References and footnotes
- Old Testament Life and Literature
- Genesis 11
- Modern Christians can argue that the baby was shown mercy as it went to Heaven without the trials and risk of Hell that those who survive to become responsible suffer. In that case God is further from being Onmibenevolent because others are not shown the same mercy though God as an onmiscient being knows who will end up in Hell if he/she survives.
- God Tests Abraham
- Mock execution
- Jephthah Kills His Virgin Daughter
- 2 Kings 3:Verse 27
- More on Human Sacrifice
- What Is the Old Testament?
- MORE CRITICISMS OF OLD TESTAMENT HISTORY