Leviticus 20:8

And ye shall keep my statutes, and do them: I am the LORD which sanctify you.

God's people are commanded to keep His statutes and to do them, to obey and to practice what He has instructed. The ground given for that keeping and doing is that He is the Lord who sanctifies them. Their holiness is grounded in His own work of setting them apart, and it is shown in obedience to His commands.

In its setting this call to holiness belongs to Israel's separation from idolatry and from forbidden dealings with spirits, with obedience to God's instruction as part of that call. That obedience includes separation from idolatry, from forbidden spiritual practices, and from other defilements. This instruction to obey and to remain separate still applies to God's people today.