In Ephesians we read:
Be very careful, then, how you live – not as unwise but as wise, making the most of every opportunity, because the days are evil. Therefore do not be foolish, but understand what the Lord’s will is. Ephesians 5:15-17
I had always associated the phrase “make the most of every opportunity” with evangelism. It pops up with an evangelistic\apologetic emphasis in Colossians:
Be wise in the way you act toward outsiders; Make the most of every opportunity. Let your conversation be always full of grace, seasoned with salt, so that you may know how to answer everyone. Colossians 4:5-6
In Ephesians, though, it is being used in a wider sense. “Be very careful how you live, making the most of every opportunity” The Ephesians passage is talking about making the most of every opportunity in life. Every opportunity to do what? The following verses tie it together with understanding the Lord’s will, (v17), instead of being drunk on wine being filled with the Spirit, (v18) encouraging one another, singing to the Lord and praising him (v19-20). The whole chapter begins by urging us to be imitators of God (Ephesians 5:1), and the verses preceding that tell us to put off our old selves, to be made new by the renewing of our minds and to put on our new selves which was made and designed to be like God. (Ephesians 4:22-24). I think Paul is saying we need to make the most of every opportunity we have of being imitators of God. This involves rejecting our old way of life and instead doing the will of God, including encouraging each other in our walk of faith. The evangeslistic sense of making the most of every opportunity in our conversations from Colossians applies under the wider umbrella of making the most of every opportunity to imitate God in all of life.