Albert Barnes Commentary 1 Peter 1:15

"but like as he who called you is holy, be ye yourselves also holy in all manner of living;" — 1 Peter 1:15 (ASV)

But as he who has called you is holy. Regarding the word called, see Barnes' notes on Ephesians 4:1.

The meaning here is that the model or example according to which they were to shape their lives should be the character of that God who had called them into his kingdom. They were to be like him. Compare Matthew 5:48 (see Barnes' notes).

So be you holy in all manner of conversation. In all your conduct. Regarding the word conversation, see Barnes' notes on Philippians 1:27.

The meaning is that since God is holy, and we profess to be his followers, we ought also to be holy.