As I answer this issue I want to be clear that it's not wrong to have a crush, to be angry (and not sin). God isn't looking down on you for having feelings, including feelings of attraction, affection or desire for marriage. I believe some desires - for justice, to enter covenant marriage, to grow a family, and to build homes that bless the world - ring deep within us because of how God made man and woman. There is a “deep calling too deep”, a part of being human, that longs for these things. These are not the ONLY way to serve God but they are also a part of His design. If you're single and longing for them, that's good, normal, and even worth celebrating. If you're single and content, Paul says to celebrate your gift of celibacy, whether if it's “for now” or long term!
But maybe you have the desire… and the timing isn't right. Or the person isn't right. Other times the desire we're dealing with is not for something good or pure or holy and when we bring it to God, it's still not removed. What then? Did God cheat us? We prayed, He didn't do what we asked. Is God not good?
This is where discernment is SO key and truth is more than necessary. Not every desire you experience, or thought you think, was sent to you by God.
Read that again.
God is not the direct cause of every feeling or desire you experience as a human. You are an image bearer in a fallen, broken world in a fallen, broken body. As an image bearer, you may desire marriage, children, a great job, community, good food - all wonderful things that God made. But in a fallen world, these things may be abused, or may vanish for a time, or may be delayed.
With Christ at your center (if indeed He is - if you have confessed Him as your one and only God) you are being shaped more into the image of Christ daily. But you will still have times when your human desires grow strong. You'll have times when thoughts pop in your head. Sometimes the desires or thoughts are completely a-moral! They aren't of themselves evil or wrong (e.g. a crush, or a desire for great food). But what you do with your desires can be holy… or not.
When I was addicted to erotica I battled this daily. A thought would come into my mind; a scene from one of those books I'd quit. I had a choice… entertain the thought or reject it. Interestingly, when I entertained the harmless thought, my desire grew. First it grew for the books, then for the sexual content, then to do the things I was consuming. It wasn't long until I had backslidden in my addiction. I would beg God to take away the feelings and when He didn't, blame God as if He was the one who caused it all.
In the years I blamed God for my feelings, I did not find freedom or contentment. How can you get free from something when you won't take responsibility for your part in the bondage? That's like a person walking into a jail, locking the door, then screaming at the jailer for putting him there.
Listen: God Himself tempts no one (James 1:13). If you're struggling with temptation, God isn't causing it - but He's ready to help you escape (1 Cor. 10:13). If you back that temptation up to the beginning, you'll likely find a moment of choice: a simple thought entertained. A train of thought endorsed. Fantasizing. Meditating. Worshiping.
Even good things can be worshipped in a manner undue them. Until our eyes are fixed on Christ and we bring these thoughts - even the good ones! - to Him for help, we'll continue to live as victims of our own lack of self control. And you know something about self control? It's a fruit of the Spirit! The Holy Spirit, given to you when you followed Christ, will MAKE you self controlled… if you let Him.
To circle back to the desire for marriage/sex/family, I want to add an important note: Getting what you desire will not fix a lack of self control regarding desire. If you let your desires run your thought life, and therefore your real life, eventually this will show up in marriage/parenting/your new job. Yes, you got what you hoped for, but your character remained unchanged. When a new desire arrives you're not ready to say “no” to it. This is how porn addictions continue into perfectly healthy sex lives. It's how we live from one discontentment to another for eighty five years.
Sometimes God doesn't take away your feelings because He expects you to take responsibility for your response to them. He won't do the work He has asked you to do. He won't make you submit to His Spirit. He won't force you to become holy. But He will offer you all the resources to get there. So when it comes to desire, let's stop blaming God for not “taking away” the thing He's using to invite us to intimacy with Him. He offers all of Himself, His whole heart, His very Spirit, and EVEN a way of escape - and we stand there offended and angry that He didn't make us into lobotomized robots.
Can you see how much He loves you? He won't sell you short. He wants to walk with you. He wants to be part of the journey of learning restraint and wisdom, of learning to become a stronger person who is not dictated by every anxious thought, controlled by every whim, or discontent with the life before them.
God didn't cause every desire you feel. But He's with you through every single one of them.