William Barclay writes on Romans 12: 9-13 with emphasis on the verse 11: “Seize your opportunities” (NSRV) also trans. as “Never be lacking zeal, but keep your spiritual fervour, serving the Lord.” (NIV):
“In a section so filed with practical advice, it is more likely that Paul was saying to his people: ‘Seize your opportunities as they come.’ Life presents with all kinds of opportunities – the opportunity to learn something new or to cut out something wrong; the opportunity to speak a word of encouragement or of warning; the opportunity to help or comfort. One of the tragedies of life is that we so often fail to grasp these opportunities when they come. There are three things which do not come back – the spent arrow, the spoken word and the lost opportunity. (my italics)”
Source: Barclay, William. The New Daily Study Bible. The Letter to the Romans, c 1975, 2002, p 195.