Where is Truth?

"If a man beats his male or female slave with a rod and the slave dies as a direct result, he must be punished, but he is not to be punished if the slave gets up after a day or two, since the slave is his property." (Deut. 21:20)

Apparently, this is a law that Moses received from an infinitely wise and holy God! There are tons of terrible verses like this scattered throughout the Pentateuch. It seems really simple to me. If a book says bad things, its a bad book; if a book says good things, its a good book. If we have to overlook parts or say that only God understands them, then I think we have a problem. Many religious cults probably have the same reasoning, “accept our holy books as truth, and if something doesn’t make sense, don’t worry about it, God knows the answer”.

For any Christian readers out there, I wonder how your faith can overcome these barriers? How do you know the Bible speaks the truth when it’s ugly untruths are so plainly seen.