12 The night is far spent, the day is at hand. Therefore let us cast off the works of darkness, and let us put on the armor of light.
Because of the imminent return of Christ, we are to “cast off” something and “put on” something.
Paul included himself in this action.
cast off [disrobe] the works of darkness,
Since Jesus might come shortly, we should put off “the works of darkness.” Those who are spiritually asleep will be captured by darkness. They will do sinful things in secret. Darkness is the natural territory of sinfulness. We see specifically what the darkness is in the next verse.
“Cast off” is a term for divesting oneself of clothes. Here it is the dirty clothes of sin. This is the negative side of “put on” in verse 14. The Greek indicates we should do this decisively (aorist). The Christian should deal with his sin by confessing them and moving on.
Eph 5: 11 And have no fellowship with the unfruitful works of darkness, but rather expose them.
“Works of darkness” refers to the sinful age in which we live.
and let us put on the armor of light.
“Armor” is military language. The believer currently lives during a period of spiritual war, a time of “darkness.” He will need his “armor of light” for this challenge. Darkness hides our sin but light exposes it. That is why people do not like the light of Scripture.
Jn 3: 19 And this is the condemnation, that the light has come into the world, and men loved darkness rather than light, because their deeds were evil.
“Put on” is a term for vesting oneself with clothes. Paul was saying we are to put on “the armor of light” in place of the cast-off “works of darkness.” The Christian life is a spiritual battle against Satan and needs the spiritual armor of light to fight him. Satan hates the truth of who God is, as revealed in His Word. We shine the bright light of who and what God is on our sin.
To put on light is to live a spiritual life. Christians must equip themselves for a spiritual battle if they are to survive the spiritual war before them (Eph 6:10-17; 1 Th 5:8).
Eph 5: 8 For you were once darkness, but now you are light in the Lord. Walk as children of light
Eph 5: 14 Therefore He says: “Awake, you who sleep, Arise from the dead, And Christ will give you light.”
1 Th 5: 5 You are all sons of light and sons of the day. We are not of the night nor of darkness.
1 Jn 1: 7 But if we walk in the light as He is in the light, we have fellowship with one another, and the blood of Jesus Christ His Son cleanses us from all sin.
1 Jn 2: 10 He who loves his brother abides in the light, and there is no cause for stumbling in him.
Christians are to do everything in the open light of day.
Many of us today fritter away time. In a practical sense we can lose opportunities by dreaming of what we will do tomorrow and lose the opportunities of today. Killing time is not murder but suicide.
We can challenge the darkness of sin in our lives by going to the light. The more we expose ourselves to God and His Word, the more we deal with our sin (1 Jn 1:5,7,9). Allowing ourselves to “walk in darkness” blunts our walk in the light.