Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness? 2 Corinthians 6:14
When Christians consented to unite with those who were but half converted from paganism, they entered upon a path which led further and further from the truth. Satan exulted that he had succeeded in deceiving so large a number of the followers of Christ. He then brought his power to bear more fully upon these, and inspired them to persecute those who remained true to God. None understood so well how to oppose the true Christian faith as did those who had once been its defenders; and these apostate Christians, uniting with their half-pagan companions, directed their warfare against the most essential features of the doctrines of Christ.
It required a desperate struggle for those who would be faithful to stand firm against the deceptions and abominations which were disguised in sacerdotal garments and introduced into the church. The Bible was not accepted as the standard of faith. The doctrine of religious freedom was termed heresy, and its upholders were hated and proscribed.
After a long and severe conflict, the faithful few decided to dissolve all union with the apostate church if she still refused to free herself from falsehood and idolatry....They dared not tolerate errors fatal to their own souls, and set an example which would imperil the faith of their children and children's children." (The Great Controversy, 45)
Reflection: Doesn't that sound like what is going on today? The Bible is laid aside for what feels good. Let our prayer be more earnest than ever, that we would not deviate from the Scriptures.