A female friend who had ended a relationship asked me a question, and my thoughts expanded from her specific situation to contemplate what's reasonable when it comes to making choices about whether to enter into or end relationships. Following is my response.
Here's my view: any type or amount of sin can be a valid reason to refrain from entering into a lifelong relationship with a particular person. The interesting thing is that since all are sinners, depending on where you draw the line, you can 'rule out' absolutely anybody depending on your preferences. So if one is to marry another, some kind or number of sins will have to be overlooked--not ignored, however, but forgiven. Just as all of our sins are forgiven by Christ, we must also be able to forgive our spouse, and to live with them knowing their imperfection and loving them in spite of it. So what it ultimately comes down to is what sort of sinfulness we can tolerate. What it is within our power, aided by the Holy Spirit, to forgive and, for the purpose of marriage, also reconcile.
Any reason can be a valid one, a good one, a justifiable one, to have broken up with [Your Ex]. In the vein of logical proofs, what is valid is not always sound, and so, even though many choices which are personal preferences may be justified, some are not always worth it. Determining which are and which are not is a matter for each individual's personal risk-reward calculus to evaluate.
My personal advice? It hinges on a few conditionals. Is there a guy that is better than [Your Ex] out there? Sure. Will you necessarily meet him and be pursued by him? That's anyone's guess. You're young yet. If you wait, you can have the benefit of a) potentially finding someone you like better, or at least figuring out what you want (to the point of visually recognizing it) and b) if leaving [Your Ex] was the wrong choice, this will become increasingly more apparent over time, and he'll still be there at the end (assuming he doesn't start a relationship with someone else, but if he does, then leaving him was more likely the right choice). Since you're unlikely to get married very soon, I would say to wait and evaluate your situation and keep tabs on your emotions as the time apart grows. And do try to benefit from relationships with other guys if you can, but not to the point of making mistakes, of course. I mainly mean friendships, wherein you acknowledge an attraction toward each other. After some time, you can reevaluate where you stand and you won't make any accidentally hasty decisions.
Feel free to take this advice or leave it, if it is of benefit to you, if you're a young woman, or for that matter a guy--but one thing is different: if you're a man, it's your responsibility to initiate the relationship and pursue her, for a number of reasons which are well worth taking more time and explaining in a future blog post on Complementarianism.
~ Rak Chazak