According to Saint Augustine to girt your loins and to have a lamp burning means to turn away from sin and then to do good works.
35 Let your loins be girt, and lamps burning in your hands.
36 And you yourselves like to men who wait for their lord, when he shall return from the wedding; that when he cometh and knocketh, they may open to him immediately.
37 Blessed are those servants, whom the Lord when he cometh, shall find watching. Amen I say to you, that he will gird himself, and make them sit down to meat, and passing will minister unto them.
38 And if he shall come in the second watch, or come in the third watch, and find them so, blessed are those servants.