God commands us to forgive others as we have been forgiven, but what about those who refuse to forgive us?
I believe it’s more important for us to forgive others than for them to forgive us. That’s because we cannot change people, we can only control how we react to other people, but we must forgive others, even if they don’t forgive us. Of course, we’d love to have those we’ve offended forgive us, but it’s not always possible. To be sure, we need to forgive others because we’ve been forgiven infinitely more by God than anyone could ever forgive us for. We had more sin before God than we’ve ever had before others, so chose to forgive. If God forgave us, then how could we not forgive others? Jesus said that “if you forgive others their trespasses, your heavenly Father will also forgive you, but if you do not forgive others their trespasses, neither will your Father forgive your trespasses” (Matt 6:14-15). 
Sometimes the problem isn’t with others; it’s with us. We cannot let go and move past what God’s already forgiven, so our standards of forgiveness for ourselves become greater than God’s forgiveness of ourselves. Jesus paid for our sins, so why do we want to keep paying for them ourselves? Imagine your child coming to you and confessing their disobedience and then you discipline them for it. Then, the very next day, they come up to you again and ask for forgiveness for the very same thing. You remind them that you’ve paid for your disobedience and you’ve forgiven them, so just let it go. Now, on the third day, they come to you again and are seeking forgiveness for the same thing they did three days ago. By now, wouldn’t you be getting a little upset that they didn’t receive your forgiveness, but that’s exactly how we may be treating God by claiming to be a believer but not forgiving ourselves. We keep going back to the throne for the same thing, over and over again, when God’s already forgiven it. We must believe God; God says, “If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness” (1 John 1:9). That should settle it, so we must extend the same forgiveness to others that God’s extended to us through Christ. There is no reason not to forgive someone. That doesn’t mean we have to be their best friend and spend a lot of time with them. If the relationship is dysfunctional, you may have to cut it off, at least for a time, but that doesn’t mean you hold a grudge against them and refuse to forgive them. If that’s the case, we’re not recognizing just how much we’ve been forgiven.
It takes the Spirit of God and the Word of God to birth the children of God, because we were dead in our sins with no hope of resurrecting ourselves (Eph 2:1-4). God had to quicken us by His Spirit and give us a new heart and with new desires, like wanting to live in obedience. Only God can change the human heart (Prov 21:1), although He may use others as a means to do so, but we of ourselves cannot change others. We can only change how we react to them, so it’s our choice to forgive. It doesn’t say to forgive only when you feel like it or only if they’ve forgiven you. A new creation in Christ (2 Cor 5:17) should have a new inclination toward Christ and desire to be living as He did, and we know that Jesus Christ died for us while still enemies of God who were wicked and ungodly (Rom 5:6-10). I hope that doesn’t offend you, but that’s what the Bible teaches. Not even one of us is good; and there are no exceptions (Rom 3:10-12), so if we, being wicked, were made righteous by the blood of Christ and forgiven through His redemptive work, why would we not want to forgive others?
God forgives us of all of our sins and justifies us in His sight through Jesus Christ (2 Cor 5:21). Now God sees us as having Jesus’ very own righteousness, so what if you’ve forgiven someone and they haven’t forgiven you? What can you do about it? All you can do is to pray that God convicts their heart to repent of it, but ultimately, it’s up to God and up to them; not us. The Bible never teaches we must force others to forgive us. Besides, if it was a forced apology, would it really be sincere? We cannot make someone forgive us, but we can make sure we don’t hold a grudge. Holding grudges is not how Jesus’ disciples react to others (John 13:34-35). It’s great to keep the door open if possible, but if they still refuse to forgive you for something you’ve confessed and asked their forgiveness for, your work is done. Pray for them and let God do what only He can do.
Many people are troubled by the belief that they’ve never been forgiven for something, even though they’ve asked for forgiveness, and many, many years have passed since the original grievance occurred. If we’re going to forgive others, we must first forgive ourselves, and after we’ve forgiven what God’s forgiven, then seek forgiveness to all whom you think you’ve offended. If they don’t forgive you, all you can do is pray about it. If they choose not to forgive you, that is on them and not you. You’ve done what God’s required, and when you’ve done that, only God can do what He can do. If we try to make someone forgive us, then we’ve missed the point. Of course it’s great to seek reconciliation, but if you’ve tried and failed, leave it up to God. Only He can direct the heart in whichever way He chooses (Prov 21:1). We can only make it worse by trying to change people.
Here is some related reading for you: Why Forgiveness is More Important for you than for Others 
Resource – Scripture quotations are from The Holy Bible, English Standard Version® (ESV®), Crossway Bibles. (2007). ESV: Study Bible: English standard version. Wheaton, Ill: Crossway Bibles. Used by permission. All rights reserved.