Tim Challies wrote a great post on this idea. I would encourage you to check it out here.
Whether you are having a good day or a bad day, the basis of your relationship with is not your performance, for even your best efforts are but filthy rags. Instead, your relationship is based on grace. Grace does not just save you and then leave you alone. No, grace saves you and then sustains you and equips you and motivates you. You are saved by grace and you then live by grace. Whether in the midst of a good day or bad, God does not base His relationship with you on performance, but on whether or not you are trusting in His Son.Enjoy