In yesterday's message I was pushing on the idea that those who have truly experienced the mercy of God will be merciful to others, even (especially) those we think are unworthy of it. I referred to Calvin and the Puritan's writing on this subject, and wanted to point you to a free resource and give you a few quotes. Calvin on Self Denial is a free eBook (pdf here, iBook here) pulled from his Institutes of the Christian Religion. In it Calvin argues that loving our neighbors (even the wicked) is impossible apart from learning self-denial from Jesus and seeing the imago dei in others.
The Lord enjoins us “to do good” (Heb 13:16) to all without exception, though the greater part, if estimated by their own merit, are most unworthy of it. But Scripture subjoins a most excellent reason, when it tells us that we are not to look to what men in themselves deserve, but to attend to the image of God, which exists in all and to which we owe all honor and love.
Because even the worst of men still retain the image of God, and are his creatures, Calvin says, "whoever be the man that is presented to you as needing your assistance, you have no ground for declining to give it to him."
Say that he is unworthy of your least exertion on his account; the image of God, by which he is recommended to you, is worthy of yourself and all your exertions. But if he not only merits no good, but has provoked you by injury and mischief, still this is no good reason why you should not embrace him in love and visit him with offices of love (Mat 6:14; 18:35; Luk 17:3).
You may think the one before you "deserves differently" from you, but consider what you, Christian, were owed by God: His justice, not his mercy. His condemnation, not his forgiveness. But in Jesus Christ you have received all mercy and been spared what you deserve. Even those who are not reconciled to God receive an abundance of mercy in this life. For all that we have gained, and have learned, from Jesus we can begin, "to love those that hate us, render good for evil, and blessing for cursing (Mat 5:44), remembering that we are not to reflect on the wickedness of men, but look to the image of God in them, an image that, covering and obliterating their faults, should by its beauty and dignity allure us to love and embrace them."
Your excuses are weak. Their need is great. Jesus has shown you the way. Go and love the unlovely.