The word ‘filthy’ is in italics; it is not in the original. There are any number of guesses why the translators have put it there.
All this is happening even among many Bible-believers, even among some sound people. The whole business of contemporary Christian worship is just a great step towards the flesh, and what the world does, and sensual things. It is just a great step towards the flesh and what the world does, and sensual things. It is lifted right out of the entertainment world which is 100% sensual. It is against the rules of Scripture but they are not listening to the Scripture. We want to be free to choose what we want to do.
There is a church a few hundred yards from this one towards the river where the pastor has decided he believes in same-sex marriage and promotes it. That is defiling the flesh, pushing beyond God’s set boundaries, strange flesh it is called in this epistle. ‘Likewise these dreamers’ dreaming their own way, irreverent towards the Word of God so they dream up their own doctrines and ideas which include defiling the flesh.