Charles Spurgeon Commentary 1 Peter 1:13-16

"Wherefore girding up the loins of your mind, be sober and set your hope perfectly on the grace that is to be brought unto you at the revelation of Jesus Christ; as children of obedience, not fashioning yourselves according to your former lusts in [the time of] your ignorance: but like as he who called you is holy, be ye yourselves also holy in all manner of living; because it is written, Ye shall be holy; for I am holy." — 1 Peter 1:13-16 (ASV)

Wherefore gird up the loins of your mind, be sober, and hope to the end for the grace that is to be brought unto you at the revelation of Jesus Christ; As obedient children, not fashioning yourselves according to the former lusts in your ignorance: But as he which hath called you is holy, so be ye holy in all manner of conversation; Because it is written, Be ye holy; for I am holy.

Do not be only moral, upright, truthful, and so forth; but be ye holy. That is a very high attainment: Be ye holy; and observe the reason for obedience to the command: for I am holy. Children should be like their fathers. There are many children who bear in their very faces evidence of their sonship; you know who their fathers were by the image that the children bear. Oh, that it were always so with all the children of God: Be ye holy; for I am holy.