The passage of scripture in verses 13 to 16 describes the influence that the Christian life should have on the world. We are a new creation (2 Cor 5:17), changed from within. The light of the world that lives in us should also shine through us. The miracles performed by Jesus caused the multitudes to glorify God (Matt 15:31), and today’s verse tell us that we too can have the same impact via our good works.
When someone performs a good work, the world will question their motivation. The world will assume that their motivation is for personal gain, or that it is some angle to get ahead at the expense of others. When the Christian performs good works because of a pure heart, intent only on serving God, the world will notice because the motivation is contrary to what is within their own hearts. A godly motivation is completely opposite to the sin nature into which we were born, and therefore good works motivated by a pure heart can only point to God, the author of all that is good. Lord may your light shine through us, and may we bless and serve the world so that our good works will glorify you in heaven.