“There are different pieces of the same puzzle.”

If there is one God, why are there so many religions?  Philosophers call this the Problem of the Diversity of Revelations.  But I was told,

(There is) no reason to think (the) diversity of revelations is a problem, any more than for a therapist to say different things to different clients (whose needs and situations differ).

That analogy didn’t take me very far.  The therapist, like a doctor, is giving advice depending on the needs of the client.  But God is giving different people contradictory stories about Himself, and also about how they should live.  Perhaps God’s messages had to start simple, when cultures were primitive, and became more adequate as cultures developed.

“Lord, do Your revelations progress from lower to higher?”

Yes and no.  Much of what I have to say is universal, and good for all times and places.  Some is quite specific to the individual and his or her circumstances, the actions he or she faces.  Some is developmental, on the side of the culture and also on My side.

“Why not just give everyone the whole truth?”

Your question has presuppositions—that I have given different, incompatible stories to different cultures.  This is only apparently true.  If you think them through, they are different pieces of the same puzzle.  Names shift but that is superficial.

“Even though one says ‘God’ and another (thinking of Buddhism) says ‘Nothingness’?”

No religion puts Nothingness in the place of God.  If it appears to, think again.  What is the role of each (name)?  Is one a substitute or replacement for the other?  And (think about) the meaning of each.  Are they really incompatible once you examine their properties?

“Perhaps each religion is like a single eye-witness report of some strange event such as a Martian landing.  The reports might be wildly different from one another.  The challenge would be to sort them out and put them into a single coherent account.”

Not exactly.  It’s not to blend the religions into a single synthesis or theology.  It’s to put them into one story.  (To take your analogy,) imagine a reporter who interviewed everyone who had an encounter with the Martians, starting at the first encounter, and wrote it up as a narrative.  Certain consistent themes might emerge, but this would be different from a scientist trying to adjudicate and synthesize the reports.  In your version (of the religions), there will be an additional unifying factor—Me.

“With life, spirit comes into play.”

For millions of years, before there was life, there was just God and a barren universe.

“You felt all alone?”

Yes, I wanted more. In retrospect, the inanimate years feel very lonely.  The emergence of life is a delight.  With life, spirit comes into play.  Wonderful to see amoeba, moss, and so forth.  The frogs (and other creatures), each with a soul and personality, each in a sense in tune with God.  I can play with the animals, “walk among them.”  I love their myriad formsI am not alone anymore.

The creatures that began to stir on the earth are amazing, more amazing than anything that had yet occurred in creation.  They move on their own, they have “internal principles of motion” as Aristotle said, have dramatic lives—even the worms and fishes.

There is birth, growth, death, mating, offspring, colonies and flocks, emergent social orders—ideality as well.  There is telos and purpose, success and failure, standards of perfection and imperfection.

And, over time, further developments in the species, a most amazing, creative ramifying of the evolutionary ladder.  New species emerge that could not have been imagined before.  Your paleontology tells the story:  the first horses could easily fit into the palm of a hand, and so forth.  Can you imagine the spectacle?

“Yes, I think I can.”