1 Corinthians 8:10
For if any man see thee which hast knowledge sit at meat in the idol’s temple, shall not the conscience of him which is weak be emboldened to eat those things which are offered to idols; For if any man see thee which hast knowledge sit at meat in the idol’s temple, shall not the conscience of him which is weak be emboldened to eat those things which are offered to idols;
The verse pictures a person who has knowledge being seen sitting at meat in the idol's temple, and warns that this sight emboldens the conscience of one who is weak to eat things offered to idols. Exercising liberty before a weak fellow believer in this way influences him to imitate the act, so that he is emboldened to stumble. The lesson is to consider how one's actions affect others and to refrain even from what is innocent in itself if it appears to support idolatry or violates another person's scruples. Even buying such offerings can look like approval of idolatrous worship.
Guarding against this requires watching at every point against unwearied temptation by watching words and guarding the spirit that prompts them. It requires standing as faithful sentinels over defective attributes of character. It requires treating with care those for whom Christ died and refusing to make crooked paths for the feet that would turn feet out of the way of life.
The stumbling block warned against is a plague spot and rock of offense that wrecks souls. It works especially by the tongue, which though a little member does a weight of mischief by sowing seeds of bitterness and putting suspicious thoughts in minds. A day is coming when every case will be revealed, and those eternally lost through such influence will look with reproach upon those who caused them to stumble.