5:3 Sexual immorality was common among unsaved Gentiles, but it is totally inappropriate for saints. Impurity is a broader term that includes all types of uncleanness (cf. 4:19). Greed is the lust for more and is essentially idolatry (v. 5).
“‘Immorality’ (RSV) and sexual perversion of almost every kind might be included under the [Greek] word porneia, translated fornication in AV; it involves all that works against the life-long union of one man and one woman within the sanctity of the marriage bond.”[191]
As children of God, saints, they cannot imitate pagans in their action - they should behave totally different.
5:4 Paul proceeded from immorality to vulgarity. The Christian’s speech should also demonstrate love (cf. 4:29). Filthiness or obscenity refers to dirty speech. Silly or foolish talk (lit. stupid words) probably describes talk that just wastes time, not necessarily “small talk.” Coarse jesting does not mean joking necessarily but vulgar joking that uses clever word plays such as double entendres. This type of speech is inappropriate for saints who should be full of thanksgiving since we have received so much. Thanksgiving is also edifying.
“All God’s gifts, including sex, are subjects for thanksgiving, rather than for joking. To joke about them is bound to degrade them; to thank God for them is the way to preserve their worth as the blessings of a loving Creator.”[192]
5:5 Paul warned his readers against improper conduct by reminding them that people who practice such things sacrifice an inheritance in the kingdom (cf. 1 Cor. 6:9–10; Gal. 5:21).
the Greek text omits the article: “does not have inheritance.” - lost eternal life.
Since Paul had already said that all believers have an inheritance in Christ (1:3–14), he was evidently contrasting unbelievers with believers (cf. v. 6; 1 Cor. 6:9–11; Gal. 5:21; Matt. 19:16; Mark 10:17; Luke 18:18). His point seems to have been that this type of behavior, which marks unbelievers, should not characterize believers.
Interpreters who take this verse as evidence that a truly saved person cannot and will not practice these vices overlook the fact that some genuine believers live carnal lives (cf. 1 Cor. 3:1–4).[193]
5:6 The sons of disobedience probably refers to certain Christians who propagate such teaching - namely that there is no need for a Christian to lead a different type of life. This particularly refer to sanctity of marriage and sexual self- control. We know that there were and are so-called Christian groups who accept worldly lifestyle in this area.
This is not a new teaching. It is already seen in the Old Testament (Gen 19; Lev 18:24–25; 1 Kings 14:24; Ezekiel 16:46–58).
5:7 Christians should not join such people, who claim to believe and with their life lie about their faith.
5:8 - This verse answers a possible question, why we should not join the sons of disobedience. It is like going back to the old ways of living. In this way, we would proclaim that nothing actually has changed in our life, that our faith has no power to transform us and set us free from the power of sin. Darkness is a symbol of sin.
Yet, we are now children of light, and even light in Christ. This transfer from darkness to light demands to be seen in our way of life.
5:9 - the fruits of light:
5:10 - Another important thing is our constant desire (Trying to discern) what is well-pleasing to the Lord.
Light dispels darkness, and then we can see all the dirt that was hidden. That is also the task of Christians. State clearly what is wrong, what is sin, what cannot be done. That is also a deed of mercy.
Thus, instead of joining the deeds of darkness, we should expose them and lead others to the truth and repentance (see Matt 18:15–16; 1 Cor 5:12; Gal 6:1).
5:14 - a combination of Is 26:19; 60:1–2.
The one who sleeps is the one who sins. Such person needs to be awaken by the teaching of the Gospel - the truth and righteousness. Through the Gospel, he can see the light of Christ, and is able to begin true life. This takes place through faith in the Gospel and baptism in Christ.
Wisdom is explained as understanding/ grasping the will of the Lord. This is important, because sin seems to have an upper hand, prevailing in society - the days are evil.
“Redeeming the time” - a beautiful phrase. We are called to redeem the time for a holy living.
“We live wisely when we use every opportunity to please and glorify the Lord. Every day and every hour provide opportunities, and we should seize them for these purposes. This is important because we live in days that evil influences and evil individuals dominate.“
Another advice is to be filled with the Holy Spirit and not drunk with wine (see Acts 2:13).
In Latin - spiritus and Spiritus refer to strong alcohol - 90%, and the Spirit. Both can influence are behavior but only the Spirit can transform us.
Then, Paul explains how we can be filled with the Spirit in 5:18 - this is taken place in our liturgy and personal prayer. But, at same time, such attitude is a sign of being filled with the Holy Spirit. A desire to pray, to sing Christian songs, to join the Eucharist comes from the Holy Spirit.
Finally, there is the call to be grateful for everything. We thank God, the Father, in the name of Jesus Christ.