That was exactly my point. It's a pick and choose smorgasbord.
"The Lord is my Shepherd"
Yes, that's nice, lets read that one out. Flip over a few pages - "dash the babies of your enemies against the rocks". Oh, that's not very nice, let's find another nice bit. "If a man lies with a male as with a woman, both of them have committed an abomination; they shall surely be put to death; their blood is upon them." Leviticus Chapter 20 verse 13.
Oh, let's flip over to the nice, new testament bit. "Love your neighbor as you love yourself." Awww , hang on, I thought new testament was nice, what's this -Do not be deceived: Neither the sexually immoral nor idolaters nor adulterers nor men who have sex with men nor thieves nor the greedy nor drunkards nor slanderers nor swindlers will inherit the kingdom of God." New Testament. No, flip back to the nice bit.
'He who is without sin, cast the first stone,' awww.
It's a mishmash.
You can either twist into a pretzel trying to explain, or you can acknowledge that it was bronze age people trying to understand the universe, doing their best but ultimately coming up with a contradictory tangle.
I do love this post @RandomBasic 
And yes, why not come up with a rational moral philosophy which you yourself can adapt to your own life experience instead of some pick-and-mix from a selection of ancient texts from another age, interpreted by a patriarchal authoritarian institution with an appalling track record tempered by some extraordinary (and highly unconvincing) mental gymnastics?
(And yes Islam is no better.)