How can believers be in the world, but not of the world

The term “world” came from the Greek word cosmos, which refers to the inhabited earth and the people who live on earth, which functions apart from God.  Taking a look at the fact we’ve established, it shows that the world is a system that is influenced by Satan. This is why Christ said” we are no longer ruled by sin, nor are we bound by the principles of the world.  Check John Ch 17:14-15. The thing that is obtainable from the world pattern is sin, the world system tend to trivialize sin. We can say that it is almost a norm to live in sin, once you’re living in the world.  For this reason, as Christians we have to set ourselves apart from the conventional things done in the world, this doesn’t mean one shouldn’t engage in activities going on in the world, but it points to how we live our lives in the midst of these activities.  The Holy Spirit is always there to minister to our hearts of things that are right or wrong, even if the world sees those wrong things as nothing. This is not a rosy task, but it is worth it and achievable, and God has told us not to conform to the pattern of the world, but to be transformed by constant renewal of the mind.