Why Jesus came down from heaven and died for my salvation, Why did he have to be crucified on the cross, and suffer for my sins? Do you know why he had to suffer for my sins? Why could he just not have said, its cool, your are forgiven. Why did his Father set it up that way? Can you answer that? Does your faith answer every mystery?
Well, I see I wasn’t specific enough

I’m pretty sure I meant to say “answer to
that mystery” and accidentally left “that” out? I denno.
Anyway, my faith doesn’t satisfy every mystery, no, but in response to the question of
why, it absolutely does!
I do agree that divine processes are completely mysterious; perfection is mysterious; the concept of an eternal continuum is mysterious. Even, when compared to the things we do know about the
physical dimension, there are infinitely more things that we
don’t know about it, and much less about the
spiritual dimension. In fact, not much at all about the spirit place is comprehensible so long as our material minds anchor our souls to the material world. I’ll agree that we are capable of understanding some of it. I’d imagine that most of us have either heard, seen, or experienced a few of the countless revival, revelation and restoration stories attributed to the work of God. Personally, what follows is a feeling I can’t quite put into words; it’s like my soul leaps for joy when I experience such things or even hear of someone else’s experience. But, comprehending the true impact of it all is impossible until we manage to shake loose the husk of our physical bodies.
As far as those 5 or 6 consecutive questions you asked, I had to resist the urge to just answer
because 
To elaborate on that, the answer to all of those questions is “because it was necessary according to the Word of God.” There is no mystery for me when it comes to
why. I have faith that however it played out was exactly how it should have played out and how it was going to play out from the beginning. That’s also regardless of how far-removed the current biblical account may be from the actual Word of God.
If we were meant to know more, then we would, but since we don’t (and overlooking the unintended support of any misconception) the answer to questions like
why did God do this a certain way is because the Word of God has expressed it all so since the beginning of time. That’s why some people affirm hopefulness by saying “If the Lord is willing!” It means that the will of God simply
is, but we have no clue what it entails. We will know it eventually, but God has always known His will in its entirety. It makes sense to me that there hasn’t been an actual decision on God’s part since the godhead collectively decided to make man in Their image. Since the decision that resulted in our immaculate inception, God has always done exactly what needed to be done at exactly the right time; we just have that tendency to screw it up. Still, God has always known every mistake we’ve made as well as those we’ve yet to make. God’s will is unerring; to err is human.
Now, as far as how it’s all done, as in
through what spiritual mediums does the Word of God decree the will of God? or
how did Jesus perform miracles on Earth? or
was one day of Creation equal to one solar day or a thousands of years of terraformation and decay? I haven’t the slightest idea other than a vague explanation that’s faith-based on something I can’t wrap my mind around. I believe the soul is somewhat aware, but the mind is stubborn and prone to decay—easily confused—incredibly gullible and susceptible to temptation. This where faith plays a major role. Why?
…because.