Are you familiar with the word 'sanctification? I have never come across this word except in a spiritual concept, but my understanding was that it means 'to set apart' so I decided to look it up. Noah Webster's 1828 Dictionary states that "it is the act of making holy" so we are in the right neighborhood as this must be a spiritual word. Then I saw the second definition and it says "setting apart for a sacred reason" and refers the reader to Genesis 2:3 where God sanctified the seventh day and rested from all His work which He had created and made. So this word has a long history in connection with our God, (wouldn't you say?) as God used it on the 7th day of creation.
This helps to understand when we find through study and prayer that God wants us to be sanctified. I see sanctification as being apart from the world or not partaking of worldly things. This explains at once how we can be in the world, but not of it, and in doing so, we can choose to serve our Lord rather than to serve Satan who is the enemy. Sanctification is a good word. Maybe we should spend some time with this word and become better acquainted with it!