You said salvation was a mystery. I replied to you that according to the Word of God salvation is not a mystery and you replied with the comment about Lazarus.
Back to the original point: salvation is not a mystery.
Catholics use the word "mystery", not to indicate something totally opaque and impossible to grasp in any sense, but as something which has an eternal, infinite and absolute dimension which is "out of our league" no matter how much we learn.
It is not like running into a brick wall. It is more like swimming through a clear coral sea. You're seeing more than you've ever seen before, but realizing that the whole thing extends farther than you can swim in every direction.
Or like being a bit of sponge floating in the ocean. The sponge may be as full of water (knowledge) as it could possible be, saturated in fact, and yet the ocean itself infinitely exceeds the capacity of the sponge to absorb.
In the same way, we can say we KNOW about salvation, but that is not to say we have fully catalogued and exhausted God's saving plan. He has more ways than we know. That's because He's God and we're not. The Bible explains this "mystery" aspect in these words:
"For high have the heavens are above the earth, So high are My ways above your ways, And My thoughts above your thoughts." (Isaiah 55:9)