Why do so many so-called Christians turn backwards to the Old Testament?

We must study both the Old and the New Testaments, in order to understand our role in the Millennial Kingdom, and how to obtain it. "Then said he unto them, Therefore every scribe which is instructed unto the kingdom of heaven is like unto a man that is an householder, which bringeth forth out of his treasure things new and old" (Matthew 13:52, KJV).

(John 14:23, 24) In answer Jesus said to him: “If anyone loves me, he will observe my word, and my Father will love him, and we will come to him and make our dwelling with him. 24 Whoever does not love me does not observe my words. The word that you are hearing is not mine, but belongs to the Father who sent me.
"The word that you are hearing is not mine, but belongs to the Father who sent me"
Jesus many times referred to the Old Testaments. Jesus many times said these words, "it is written", "did you not know, it was written"

(2 Timothy 3:16, 17) All Scripture is inspired of God and beneficial for teaching, for reproving, for setting things straight, for disciplining in righteousness, 17 so that the man of God may be fully competent, completely equipped for every good work.

True the many laws given by God no longer exist but the principles still can be applied.

If you were to witness a madman in a school yard hacking little children to death and you had access to a rifle, what do you think God would want you to do? Obey the law, "Thou shalt not kill", or take the mentally sick animal out and save the lives of many children?

To obey the black and white letter of the law, can only bring death. It is not the written law that we should obey, but the spirit of the law.

I tell you now that you can lie
There is a time to steal
There is a time to disobey
There is a time to kill
There is a work that must be done
Upon the Sabbath day
No one who understands the Lord
Would teach another way
For the spirit judges not on what you do
The heart and soul of man he searches through
It's the 'REASON' why the deeds of man are done
This is what the Lord God judges on.