What are these "works of darkness" which we must avoid? Some of these works are enumerated in Romans 13:12-13: "Let us therefore cast off the works of darkness, . . . not in rioting and drunkenness, not in chambering and wantonness, not in strife and envying." A Christian is thus to "cast off" all such works of darkness from his or her own life, to "have no fellowship" with those who practice them, and even to openly "reprove them."
"This I say therefore, and testify in the Lord, that ye henceforth walk not as other Gentiles walk, in the vanity of their mind, Having the understanding darkened, being alienated from the life of God through the ignorance that is in them, because of the blindness of their heart: Who being past feeling have given themselves over unto lasciviousness, to work all uncleanness with greediness" (Ephesians 4:17-19). Such works of darkness stem directly from a denial of God as sovereign: "When they knew God, they glorified him not as God, . . . and their foolish heart was darkened" (Romans 1:21). This darkening of the heart is soon followed by a darkening of the life: "Wherefore God also gave them up to uncleanness. . . . Even as they did not like to retain God in their knowledge, God gave them over to a reprobate mind, to do those things which are not convenient" (Romans 1:24, 28).
In these days of moral confusion, with attitudes and actions once outlawed by society now being defended and favored (e.g., sexual promiscuity and perversion), and with once-honored attributes now ridiculed (e.g., chastity, spirituality), there are great pressures on Christians to compromise with these works of darkness. God and His standards do not change, however, and He still expects us to shun and reprove them. HMM
http://www.icr.org/article/6371/