These common words echo the sentiment of other sayings including the Latin carpe diem, which translates in English as “seize the day.” Also familiar is “eat and drink, for tomorrow we may die.” (1 Corinthians 15:32) The context of these words means so much. If the focus is on the here and now, then it is a call to make the most of things, perhaps meaning, literally, eat and drink as much as you can if that is what you seek the most. If the focus is on a post-death judgment then the words are heard to mean, “get right with God” so that, if it is your last day, then you have be ready for judgment.

James 4:13-15
Come now, you who say, “Today or tomorrow we will go to such and such a town
and spend a year there, doing business and making money.”
Yet you do not even know what tomorrow will bring. What is your life?
For you are a mist that appears for a little while and then vanishes.
Instead you ought to say, “If the Lord wishes, we will live and do this or that.”

This verse does not speak of pending judgment that you must prepare for. On the contrary, it speaks about the great uncertainty about anything in the future. It is precisely a call to live in the moment, to seize the day and to be radically and mindfully present. Tomorrow is within God's hands so any planning about tomorrow is presumptuous. Live everyday as if it were your last. And enjoy doing so!