Let your light shine before others, so that they may see your good works and give glory our Father who is in heaven.
Matthew 5:16

Holiness is required, that we may not be a disgrace to God and a dishonour to him. The sin of God's people stains his honour and profanes his name. When men profess to be a people near God, and live carnally and loosely, they dishonour God exceedingly by their conversation. Men judge by what is visible, and so they think of God by his servants.

Since Christ was holy, certainly Christians should live more temperately, justly, and soberly. Men are apt to think of God by his worshippers, and by the people that profess themselves near and dear to him; therefore it concerns us to walk so, that our lives may honour him. There is no way to honour God entirely and sincerely until we have learned both to know and to do his will. Otherwise we do but serve Christ as the devil served him, who would carry him upon the top of the mountain, but with the intent to bid him to throw himself down again. So we seem to exalt God much in our talk and profession; yea, but we throw him down, when we pollute him and deny him in our conversation.

Our lives are the scandal of religion, and a pollution and blot to the name of God. So with respect to ourselves, you see what need we have to go to God, that he will give us grace that we may please him and glorify his name. Also a Christian should desire all others around him to also glorify God. A fire turns all things near it into fire, and leaven spreads until it has subdued the whole lump. So is the nature of grace, it loves to spread itself. We love to reach and diffuse our influence on others. False professors are not interested in those about them, but a true Christian will be earnest, and much in this matter. Therefore we need to be much in prayer that God's name will be hallowed!

Thomas Manton, Works, i:78-79