There can be opportunity sought for evil. Paul wrote of the wicked, "Their feet are swift to shed blood" (Rom. 3: 15). Such people seek occasion to perform their mischief. Perhaps the best known man of infamy is the betrayal of the sinless Son of God, Judas Iscariot. Regarding Judas we read, "And from that time he sought opportunity to betray him" (Matt. 26: 16).
Opportunity for doing good. The Greek words translated "opportunity" basically suggest a "fit season." Circumstances can often be such that one can be afforded a chance for doing a good deed. Hear Paul: "As we have therefore opportunity, let us do good unto all men, especially unto them who are of the household of faith" (Gal. 6: 10). Paul realized that the prevailing circumstances might be such as to not be conducive. On the other hand, he is saying, the condition could be favorable.
As acknowledged, there are several factors in determining the shaping of life's situations. Desire and values, though, usually determine our decisions to act or not act relative to opportunity. For instance, the writer of Hebrews mentioned concerning certain faithful ones of old that, "If they had been mindful of that country from whence they came out, they might have had opportunity to have returned" (Heb. 11: 15). Let us be ready to every good work (Tit. 3: 1).