I only believe it because the bible says so.
So then you also believe in owning slaves,
However, you may purchase male or female slaves from among the foreigners who live among you. You may also purchase the children of such resident foreigners, including those who have been born in your land. You may treat them as your property, passing them on to your children as a permanent inheritance. You may treat your slaves like this, but the people of Israel, your relatives, must never be treated this way. - (Leviticus 25:44-46)
rape,
As you approach a town to attack it, first offer its people terms for peace. If they accept your terms and open the gates to you, then all the people inside will serve you in forced labor. But if they refuse to make peace and prepare to fight, you must attack the town. When the LORD your God hands it over to you, kill every man in the town. But you may keep for yourselves all the women, children, livestock, and other plunder. You may enjoy the spoils of your enemies that the LORD your God has given you. - (Deuteronomy 20:10-14)
murdering children,
From there Elisha went up to Bethel. While he was on his way, some small boys came out of the city and jeered at him. "Go up baldhead," they shouted, "go up baldhead!" The prophet turned and saw them, and he cursed them in the name of the Lord. Then two shebears came out of the woods and tore forty two of the children to pieces. (2 Kings 2:23-24)
"Then I heard the LORD say to the other men, "Follow him through the city and kill everyone whose forehead is not marked. Show no mercy; have no pity! Kill them all old and young, girls and women and little children. But do not touch anyone with the mark. Begin your task right here at the Temple." So they began by killing the seventy leaders. "Defile the Temple!" the LORD commanded. "Fill its courtyards with the bodies of those you kill! Go!" So they went throughout the city and did as they were told." (Ezekiel 9:5-7)
Shall I go on?