Today I'm struggling to keep "just today" in mind. I have a lot of things on my plate - tomorrow, and Sunday, and next week - but God hasn't asked me to think about all of those things today. He says, "Do not worry about tomorrow. Today has enough worries of its own. (Matthew 6:34)"
God teaches us to live one day at a time. Think about creation. He could've created everything in the world in an instant (snap!), but He didn't. Instead He created something and then called it a day. Think about the manna. He provided only what was needed for the day. When the Israelites tried to gather extra for tomorrow, it rotted.
19th Century author and preacher, Andrew Murray, writes: "If time had been given to man in the form of one long unbroken day, it would have exhausted and overwhelmed him. Broken small and divided into fragments, he can bear them; only the care and the work of each day have to be undertaken -- the day's portion in it's day. We are so easily led to look at life as a great whole, and to neglect the little today."
And so here's to today. All 16 (or so) waking hours. From the rising of the sun to its setting. What has God asked you to do -- just today?