Colossians 4:5

With respect to his readers’ relationship to unbelievers, Paul counseled the use of wisdom as most important. This involves living life in the light of God’s revelation and then applying this knowledge to specific situations (Colossians 1:9). The Greek word translated "opportunity" (kairos, lit. time) probably implies the opportune time, as it does in some other places. The opportunity in view seems to be the opportunity to bring others into full union with Christ (cf. Colossians 4:3).