From Northridge church of Christ
“Therefore do not worry about tomorrow… ” (Matthew 6:34). A person’s life can be divided up into four chunks of time: the past, the present, the future and eternity. The devil draws attention to the past and the future; God draws attention to the present and eternity. Therefore, the devil wants to take our focus off of the present and eternity while God wants us to avoid investing too heavily in the past and the future.
For example, when a person is thinking about becoming a Christian, the devil attacks that thinking in at least two places. First, the past: “I have done too many bad things that God could never forgive me of,” and second, the future: “Even if He could forgive me, once I was baptized, I could never live up to the high standard of the Christian life.
God, on the other hand, reinforces truthful thinking in the above scenario by coaching a person to do NOW what will secure him or her for ETERNITY. In the process, of course, God does remedy the guilt of sin (PAST) and also gears the new convert up by prayer, worship, Scripture, fellowship, hope, etc. to be faithful in living out the Christian life (FUTURE).
The plea to live in the present saturates Scripture (see for example Mt. 6:34; 2 Co. 61-2; 2 Pet. 3:11-12).
That does not mean we have no business with the past. There may be a mess to clean up. And it does not mean we have no business with future, because we must plan (see Jas. 4:13-16).
It does mean that we should not waste life fantasizing, “I wish I could go back to yesterday,” or “I am waiting for things to be different tomorrow.”
Rather, live in the moment. Do what you are supposed to be doing today. Obey God now. Take responsibility for the present. That posture is Christian” and can secure our eternity.