well i don't know that i'd agree the Bible isn't a 'puzzle book'
there are many deep things in it, hard to understand and needing much prayer, meditation and study to comprehend.
Christianity is a thinking 'religion' -- it's not about what we do by which we are saved, but about what we believe. belief is a mental property, not a physical property. God expects us to think; He is a God of intelligence and He wants us to use our minds, to study, to know, to seek out understanding and teach and encourage one another with it. we are to be wise, to love wisdom and look for it. it's His will that we 'think on' whatever is good and pure and perfect and holy.
God hides things. He says cryptic things. He makes mysteries and reveals mysteries. He gives dreams and visions, and speaks parables and proverbs -- i rather think that the fact He does these things means we should devote time to trying to 'puzzle them out' -- not that He never speaks clearly, because clearly He does lol, but He also speaks in such a way that it's incumbent on us to think and reason and search out the full extent of what He means. not entirely unlike a puzzle.
kinda like you find a way not to believe it when the Bible clearly says many times that Christ died for all?
that is not what's meant by 'comparing spiritual with spiritual' and it isn't the kind of thinking God intends for us to do.
when the Bible says something you are not expecting it to say, you need to apply your mind to figuring out what it means that God has said this -- not to try to figure out how to make it not say what it literally says.
in Acts 11 they are amazed and glorify God because it has been made evident that God has granted the Gentiles repentance to life.
it doesn't say *some* and it doesn't say *all* it says "Gentiles"
it's not informing us that salvation is being held out to every individual nor is it informing us that salvation is being held out only to a narrow preselected group. it's informing us that the people being saved in Christ by grace through faith & repentance to life and belief are not exclusively Jews
the point here is that Gentiles, not just Jews, are included in Joel 2:28/Acts 2:17
it's a statement about God giving signs and evidence of the elimination of Jewish exclusivity -- about Deuteronomy 32:21 being fulfilled.
'having a sound mind' isn't about eisegetically twisting and editing scripture to force it into saying things it doesn't say.
we need to figure out what the things it does say mean.
good grief, look at Acts 10, wow, it comes right before Acts 11. maybe the context is relevant, huh?