I've often heard it said- "Yesterday is history, tomorrow is a mystery, and today is a gift, that's why they call it the present." Someone else said, "The past is a cancelled check, tomorrow is a promissory note, today is the only cash that you have, so spend it wisely."
Slogans or quotes like that sometime become cliche, when they are repeated so often. But isn't this really a truth that we should embrace and thank God for ?
Another truth that seems to be interwoven into this is that of our mortality and human condition. We are told to "humble ourselves" and to "draw nigh to God". (James 4) God talks about those in the world who are lifted up and given prominence. Oftentimes this leads to their pride and fall. God provides for our daily needs, he also promotes whomsoever he chooses.
Believers who know God is faithful should practice this truth on a daily basis. "God is God, and I ain't him." Acknowledge. Trust. Proverbs 3:5,6; Philippians 4:6 & 7; Mark 11:24; Hebrews 11:6. These are all good reminders of who God is, and who we are. Let's be wise enough to put ourselves in the proper place.
If we do this, we can face each day as if it is a Gift from God. We will learn not to worry about the past, and not to fret about the future. All of this is in his hands. He is working everything out for our good, if we are following and trusting in him.