Found twenty-one times in the New Testament, the Greek noun “didaskalia” meant “instruction” or “teaching.”  There are the religious “doctrines” of men which condemn (Mt. 15:9; Mk. 7:7).  The Old Testament is for our “learning” (Rom. 15:4).  People may be carried about by every wind of “doctrine” (Eph. 4:14).  Some teaching is contrary to sound “doctrine” (1 Tim. 1:10).  There are the “doctrines” of devils (1 Tim. 4:1) as well as “good doctrine” (1 Tim. 4:6).  Heed is to be given to “doctrine” (1 Tim. 4:13, 16).  It is possible to “labor in doctrine” (1 Tim. 5:17).  There is the “doctrine” according to godliness (1 Tim. 6:3).  We read of “sound doctrine” in Tit. 1:9; 2:1.