DONOT BE BOUND TOGETHER WITH UNBELIEVERS; FOR WHAT PARTNERSHIP HAVE RIGHTEOUSNESS AND LAWLESSNESS, OR WHAT FELLOWSHIP HAS LIGHT WITH DARKNESS?
Or WHAT HARMONY has Christ with BELIAL, or WHAT HAS A BELIEVER IN COMMON WITH AN UNBELIEVER?
Or WHAT AGREEMENT HAS THE TEMPLE OF GOD WITH IDOLS? For WE ARE THE TEMPLE OF THE LIVING GOD; just as God said, “I WILL DWELL IN THEM and walk among them; And I WILL BE THEIR GOD, AND THEY SHALL BE MY PEOPLE.
THEREFORE, COME OUT FROM THEIR MIDST AND BE SEPARATE,” SAYS THE LORD”. “And DO NOT TOUCH WHAT IS UNCLEAN; AND I WILL WELCOME YOU.
“And I WILL BE A FATHER TO YOU, AND YOU SHALL BE SONS AND DAUGHTERS TO ME,” Says the Lord Almighty. (2 Corinthians 6:14 – 18 NASB Emphasis added)
Why does God instruct His people to separate themselves from these unbelieving churches? He answers this question in another passage:
You were running well; WHO HINDERED YOU FROM OBEYING THE TRUTH? This persuasion did not come from Him who calls you. A LITTLE LEAVEN LEVENS THE WHOLE LUMP OF DOUGH. (Galatians 5:7 – 9 NASB Emphasis added)
Oh, Machen eventually did separate after trying to turn back the liberal tide by founding the Orthodox Presbyterian Church.