Khloé Kardashian’s getting real about faith … saying she was just reunited with a major keepsake — after Kim swooped in and bought their late dad’s Bible the second TMZ reported it was hitting the auction block.

The reality star spilled it all on her “Khloé In Wonder Land” podcast Wednesday … claiming Ellen Pierson married her dad on his deathbed and cleaned house — so when the Bible popped up at auction, they knew they had to snatch it back.

Turns out it was the Bible Robert once passed to O.J. Simpson back in the day — and just last month on “The Kardashians,” Kim revealed she secretly dropped $80K on it at auction … all to gift it back to Khloé.

Khloé said getting it back meant everything — the front still has her dad’s name etched in gold, and inside was a handwritten note from him … making the whole thing feel special.