I am sure Einstein made mistakes (mathematically, and otherwise). He wasn't god either. I'm sure his knowledge was finite. He didn't know everything about everything. Was he an intelligent and gifted man? For certain, he was indeed! But gifted men make wrong conclusions, and Albert Einstein didn't know everything, and about this topic I believe he had no real knowledge.
To assume that Einstein was right about God because he knew a lot about a lot of things, is akin to saying that you can trust a rocket scientist to do brain surgery, simply because he/she is brilliantly gifted at sending a spacecraft to the stars! Anyone willing to do that, should well, get their brain examined (and by a real neurosurgeon)!

Einstein didn't know God. The Bible says that spiritual things are spiritually discerned. Perhaps that is why Einstein didn't discern God, because he didn't have any kind of spiritual discernment.
Regarding his thought that the Bible is merely a collection of fables, I might Quote from the NKJV Bible.
1Corinthians 1:18 "For the message of the cross is foolishness to those who are perishing, but to us who are being saved it is the power of God."
So, we can see, that thousands of years before Einstein was even a glimmer in his daddy's eye, the Bible already talked about his attitude toward it.

As for those confusing the organized religions with true worship of God, well, they are not one in the same. Yes, many evils have been done in the name of god, and in the name of religion, but that doesn't mean that God approves them. Those actions are rather a mere distortion of God by His adversary, who is a murderer and liar, and has been so from the beginning.