Ephesians 5:15

(5:15,16) "Wisdom" is the application of biblical principles to your personal experience. Anything else would be living according to the dictates of the Old Nature, driven by the father of deceit. Here, "opportunity" refers back to "how you live". Too often, we read into that instruction "witnessing" rather than "living". Then we compound the error by extending the instruction to "witness in the manner and after the pattern of how I witness". Sometimes the methods of the local assembly for witnessing, whether it is a set time for visitation, or passing out tracts at particular events, or even the biannual revivals, all become the definition of 'witnessing' adopted by the whole assembly. Anyone who is not participating in the sanctioned activities is considered to not be witnessing. That is not the intent of this instruction. The entire thought is an extension of "live as children of light" and carries us into every moment, not just isolated moments of perceived spiritual service. Our life is our spiritual service. Remember Romans 12--"Present your bodies, a living sacrifice".