Not only does God exist, but He makes it known. There are so many prophecies where God says "then you shall know that I am God." God wants our attention--and He will get it; and He might resort to smacking us over the head with a 2 x 4 if that's what it takes.
I can't tell you how many lessons are available to us through this trial. And oh what an opportunity to take hold and learn them! There's always going to be the question: WHY? And the more I think about it, the more I come to the same answer every time: Because I'm building my character in you, My child. I really think it's up to us to decide just how much we will let a trial like this teach us.
I've started noticing a pattern in life. There are times when you get a kick in the butt, when you have a sudden stare-in-the-face about what you need to be doing, or about what you need to stop doing, and you cry out to God, with real tears, and in the deepest emotion that you've never experienced before. You repent, and start afresh, believing God has forgiven you and is right by your side in your endeavors to a new and different path that you are finally ready to begin. And life is good because there is nothing sweeter than breaking through to God who showers His tender mercies over you. God just worked a miracle, lifting you from the depths of despair--yes, a miracle because even you couldn't have pulled yourself out. Only God. You have never been more grateful. You praise God. Without God, there is no worth, no value, no purpose for anything. You are on fire. On fire for God. You set new goals, along with your newly molded positive outlook, ready to work for God. Ready to give your life, once again, to God in everything you think, say, and especially do. You are ready to go to extremes for God, even if it means cutting off your right arm or plucking out your eye if they are holding you back. And your prayers, strong, bold, and full of His Holy Spirit are being answered right before your eyes. 
You quit praying altogether because it's not effectual. They're not riveting prayers. You want back that strong relationship you had with God, but your prayers are not getting answered and you just can't seem to focus. You sit down to read and you can't even remember the sentence you just read. You stop trying. You take a week and then a month to shake this rut you're in. Suddenly, things seem familiar. You've been here before. You're back in the trenches of desperation. How did this happen? When did it start? The epiphany you need, or the major lesson to learn from it all is not so suddenly revealed just because you see there's a problem. It's only the beginning. And whatever that lesson is (I have found, many times it's the same lesson in times past--only to be understood more deeply), you are taken back to square one: repentance. Back to those real tears. Back to God. Somehow, despite the prayers and studying, the fasting and mediation, despite all your efforts, you got away from God and began relying on yourself; your efforts, your good deeds. You lost sight of God's goodness. Isn't this the lesson of Job? Living righteously, keeping God's commandments--yes, good things, but without the "Who Am I" attitude, it is in vain because it is only a man's effort. When will you learn? "Truly every man at his best state is altogether vanity. Selah." (Psalm 39:5)God is so merciful and has ways of bringing us back to Him. It's never as simple as God knocking on your door, or calling your phone to tell you, "here's the problem. Let's work on it." But perhaps all along, God does poke us, and He nudges, pushes, shoves, then finally, smacks us over the head to stop us in our tracks.
