"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." - Manuel II Palelologus
Thats a bunch of bull. It happened in the Bible yes, but show me where God sanctioned it.
I can show you where Jesus taught against it.
Or do you prefer to ignore those?
Genesis 16
1 Now Sarai, Abram's wife had borne him no children, and she had an Egyptian maid whose name was Hagar.
2 So Sarai said to Abram, "Now behold, the LORD has prevented me from bearing children. Please go in to my maid; perhaps I will obtain children through her." And Abram listened to the voice of Sarai.
3 After Abram had lived ten years in the land of Canaan, Abram's wife Sarai took Hagar the Egyptian, her maid, and gave her to her husband Abram as his wife.
4 He went in to Hagar, and she conceived;
And in the very next chapter, God makes the Abrahamic covenant with Abraham!
Genesis 17
1 Now when Abram was ninety-nine years old, the LORD appeared to Abram and said to him, "I am God Almighty; Walk before Me, and be blameless.
2 "I will establish My covenant between Me and you, And I will multiply you exceedingly."
3 Abram fell on his face, and God talked with him, saying,
4 "As for Me, behold, My covenant is with you, And you will be the father of a multitude of nations.
5 "No longer shall your name be called Abram, But your name shall be Abraham; For I have made you the father of a multitude of nations.
6 "I will make you exceedingly fruitful, and I will make nations of you, and kings will come forth from you.
7 "I will establish My covenant between Me and you and your descendants after you throughout their generations for an everlasting covenant, to be God to you and to your descendants after you.
I'd say that is about as much approval as you can get!