Allah Or God

Common sense should reveal to a person that with one God, why are there so many religions or
organizations in the world?
All seven churches in Revelation Chapters 2-3 is written that," those that overcome," I would be surprised if it doesn't mean the false doctrine of the religious organizations.
#1. Those that overcomes will I give to eat of the tree of life, (that I received;) #2. the hidden manna;
#3. power over all the nations; #4. shall not be hurt of the second death; #5. white raiment with your name written in the book of life; #6. he shall go no more out; (neglect me) #7. shall not be hurt of the second death.
If the Old Testament worked, why did Jesus the Son, have to die on the cross? It reads that a person must exceed the righteousness of the scribes and Pharisees, ye shall in no case enter into the kingdom of heaven. Wouldn't that be the Old Testament doctrine?
God never sent Paul, how can a person expect his rant to get you into the kingdom of God, for eternity's sake?
The author's name is Elijah the prophet of Malachi; Behold I will send you Elijah the prophet before the coming of the great and dreadful day of the Lord. and he shall turn the heart of the fathers to the children, and the heart of the children to their fathers, lest I come and smite the earth with a curse. (Mal. 4:5-6)