1 Timothy 4:1,2,16

1 But the Spirit says expressly that in later times some will fall away from the faith, paying attention to seducing spirits and doctrines of demons,  2 through the hypocrisy of men who speak lies, branded in their own conscience as with a hot iron; 

16 Pay attention to yourself, and to your teaching. Continue in these things, for in doing this you will save both yourself and those who hear you.