2nd Corinthians 11: 12-15 is where the idea of Evil masquerading as light comes from:

(NKJV)

12But what I do, I will also continue to do, that I may cut off the opportunity from those who desire an opportunity to be regarded just as we are in the things of which they boast. 13For such are false apostles, deceitful workers, transforming themselves into apostles of Christ. 14And no wonder! For Satan himself transforms himself into an angel of light. 15Therefore it is no great thing if his ministers also transform themselves into ministers of righteousness, whose end will be according to their works.

Here's an older CCM Song that also fits: https://www.youtube.com/watch?v=HMO0qNwshTQ

Farrell & Farrell - Hidden Agenda

2nd Corinthians 11: 12-15 is where the idea of Evil masquerading as light comes from:

(NKJV)

12But what I do, I will also continue to do, that I may cut off the opportunity from those who desire an opportunity to be regarded just as we are in the things of which they boast. 13For such are false apostles, deceitful workers, transforming themselves into apostles of Christ. 14And no wonder! For Satan himself transforms himself into an angel of light. 15Therefore it is no great thing if his ministers also transform themselves into ministers of righteousness, whose end will be according to their works.