And that ye may put difference between holy and unholy, and between unclean and clean;
To make a difference between the unclean and the clean, and between the beast that may be eaten and the beast that may not be eaten.
Ye shall therefore put difference between clean beasts and unclean, and between unclean fowls and clean: and ye shall not make your souls abominable by beast, or by fowl, or by any manner of living thing that creepeth on the ground, which I have separated from you as unclean.
And ye shall be holy unto me: for I the LORD am holy, and have severed you from other people, that ye should be mine.
Therefore thus saith the LORD, If thou return, then will I bring thee again, and thou shalt stand before me: and if thou take forth the precious from the vile, thou shalt be as my mouth: let them return unto thee; but return not thou unto them.
Her priests have violated my law, and have profaned mine holy things: they have put no difference between the holy and profane, neither have they shewed difference between the unclean and the clean, and have hid their eyes from my sabbaths, and I am profaned among them.
And they shall teach my people the difference between the holy and profane, and cause them to discern between the unclean and the clean.
Unto the pure all things are pure: but unto them that are defiled and unbelieving is nothing pure; but even their mind and conscience is defiled.
1 Peter 1:14-16
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.