This is a difficult one (even for believers) when we find ourselves in the middle of a storm and don't see a way out.
Since accepting Christ, I learned a couple of things early on. One is that "God" is not out to harm us. Sounds "logical", but how often do we blame God when things go wrong in our lives? I know I did. But the fact is, He loves us and is trying to arrange things in our favor, and for our own good , "independent" of our current circumstances. The dilemma is that many times, the current storm we are facing is so powerful that it is ripping our heart out and causing us to question our faith.
So, why would God allow (not cause) these struggles. I believe there are a couple of reasons. One could be that He wants a relationship with you if you've been running from Him your whole life, but even if you haven't, it could be He wants to see how strong your faith really is (the book of Job is an excellent study of the testing of one's faith). Will you trust Him in times of sorrow, as you do, in times of joy? Or, will you discard and even curse Him, only to come back when you "need" something again. Now, don't get me wrong, God ALWAYS wants you back should you stray from Him, but how much stronger will your relationship be with Him if you can stand firm in your faith during the most trying times?
The other reason we could be facing a storm is that God sees something in your future that he needs to get you prepared for (or out of the way of). Perhaps a new job, a new relationship, or maybe even an event He doesn't want you to be around (or a part of) 10 years from now! Remember, God is everywhere, including the future. A current storm could be God's way of saying, "I need to move you out of the way of this FUTURE event (or suffering)" or "I have something better planned for you than this current job, relationship or calling in life". God will allow this current struggle in your life to either get you to listen, move, or maybe even "mend" a relationship, so that the future GOOD is allowed to play out. Will you trust Him?
There may be times during these current storms where you can't possibly see the "good" that can come out of it. And you know what? That's o.k. You're allowed to feel that way. And certainly don't feel bad or guilty about it. Here's why, if you saw everything that was going on, knew how it was all going to fall into place in the future, and thus never had a doubt, well, then, you'd be God! And God would never allow you to become so arrogant as to THINK you were Him! So, trust God in your current storm, no matter how painful it is. I know it's not easy, but each time the pain seems to get worse, spend even more time with Him. He wants to help. He really does. God's strength is perfected in your weakness. The weaker you become the stronger God will be!
And lastly, that "good" I mentioned above? It will appear (though maybe not on your timetable). In fact, it may turn out to be something you never thought you ever wanted. But instead, turns out to be something God knew you NEEDED and you'll end up glorifying Him for it!
"My thoughts are nothing like your thoughts," says the LORD. "And my ways are far beyond anything you could imagine." Isaiah 55:8. Trust that God is working things out for you, even when you can't see it. For as much as you care about what's going on today, God has an even BIGGER plan for your future and "your" eternal well being so trust Him.