1 Peter 1:16

because it is written, "Be holy, for I am holy."

Surrounding context

1:15 but as He who called you is holy, you also be holy in all your conduct,

1:16 because it is written, "Be holy, for I am holy."

1:17 And if you call on the Father, who without partiality judges according to each one's work, conduct yourselves throughout the time of your stay here in fear;

Translation and sources