When Paul mentions being beaten, and not yet killed, perhaps he was thinking of Psalm 118:18, where the Psalmist writes: The Lord has chastened me severely, but he has not given me over to death.
10 In the eyes of the world, Paul appeared sorrowful. Yet, in fact, he was always rejoicing (see Matthew5:11-12; Romans 5:3; Philippians 4:4).
In the eyes of the world, Paul appeared poor; he appeared to possess nothing. Yet, in fact, Paul was immensely rich (see Ephesians 1:7; 2:7; Philippians 3:7-8; 4:19). In Christ, Paul possessed everything (see Romans 8:32). He preached to others the unsearchable riches of Christ (Ephesians 3:8,16). Paul followed the example of Christ: though [Christ] was rich, yet for your sakes he became poor, so that you through his poverty might become rich (2 Corinthians 8:9).
We Christians may have no “silver and gold” to give to others, but that which we have we can give in abundance: namely, the unsearchable riches of Christ (see Acts 3:1-8,16).
Let us ask ourselves: How much is our life like Paul’s life? Do we act as though we possessed these spiritual riches? Do we persevere when trials and persecution come? Do we endure in silence when others revile us? Paul has set for us such a high standard, such a high example! But even though Paul’s example is high, through God’s grace and the Holy Spirit’s help we can follow it; we not only can, we must!
11 Paul has spoken freely to the Corinthians; in every matter he has spoken plainly and openly. Paul’s heart is opened wide to the Corinthians; that is, his heart is filled with love for them.
12 Paul writes to the Corinthians: We are not withholding our affection from you; we are not restricting our affection for you. But, says Paul to the Corinthians, you are withholding [your affection] from us; it is your affections that are restricted. Paul’s love for the Corinthians is “wide”; but their love for him is “narrow.”
13 Just as a father would ask a favor from his children, so Paul asks the Corinthians to open wide [their] hearts to him—to enlarge their love for him.
14 Do not be yoked together with unbelievers—with wickedness, with darkness. What does Paul mean here? His meaning is this: Christians must not live and work in partnership with those who deny Christ.
For example, a believer must not marry an unbeliever (see 1 Corinthians 7:39). But if one becomes a Christian after being already married, the believing partner should not leave his or her spouse (1 Corinthians 7:12-13).
Paul has written that it is all right for Christians to eat with unbelievers (1 Corinthians 10:27). Furthermore, it is necessary to have some association with sinful and evil people (1 Corinthians 5:9-10). But we must take no part in their sin and evil. Especially we must not take part in the worship of idols.
It is impossible for light to have “fellowship” with darkness. God is light; in him there is no darkness at all (1 John 1:5-7). We must live as children of light (Ephesians 5:8). Jesus Christ is the light of men (John 1:4-5); He is the light of the world (John 8:12). Believers in Christ have been called out of darkness into his wonderful light (1 Peter 2:9). To reject Christ is to walk in darkness (see John 3:19-20).
15 What harmony is there between Christ and Belial?18 What does a believer have in common with an unbeliever? The believer’s life is lived for Christ; the unbeliever’s life is lived for self. The believer’s treasure is in heaven; the unbeliever’s treasure is on earth. The believer seeks the praise of God; the unbeliever seeks the praise of men. How, then, can the believer and unbeliever work together?
16 We believers are God’s holy temple (1 Corinthians 3:16; 6:19; 1 Peter 2:5). The word “holy” means to be separated from evil and sin. There must be no evil, unholiness, or idol worship in us, in our “temple” (see 1 Corinthians 10:20-21). Our temple (body) must remain holy, because God is living there.
Paul here quotes from Jeremiah 32:38 and Ezekiel 37:27. Where God’s people are, there will God also be. Therefore, God’s people (the church) must be holy, because God can tolerate no unholiness.
17 Therefore come out from them and be separate (Isaiah 52:11). From whom must we come out and be separate? From unbelievers, from evil doers, from those who walk in darkness. Have nothing to do with the fruitless deeds of darkness (Ephesians 5:11). … you must not associate with anyone who calls himself a brother but is sexually immoral or greedy, an idolater or a slanderer, a drunkard or a swindler. With such a man do not even eat (1 Corinthians 5:11). One sin can make a person’s entire life impure; one unrepentant sinner can make the entire church impure (see 1 Corinthians 5:6-7).
Even though all of this is true, we must be careful how we act upon it. Because these verses do not tell us to separate from a brother simply because we have a disagreement with him over some matter. No, we must not separate in this way. One of Satan’s chief methods for dividing the church is to lead Christians to judge each other, to condemn each other, and to accuse each other of being false Christians.
Many churches have been split apart because of this. And those people who split the church in this way often quote this very verse to justify their actions: … come out from them and be separate. But along with this verse, those people should remember another verse, the command of Jesus: “Do not judge” (Matthew 7:1).
In Christ’s church both purity and unity are essential. We need the very clear guidance of the Holy Spirit to know when to separate from a brother, or to come out from a church. If for any selfish, impure, or false reason we condemn a brother or a church, we are committing a far greater sin against the body of Christ than the sin we are accusing our brother of. In these matters let us be humble; and let us also remember that as we judge others, so God will judge us (Matthew 7:2).
Therefore, we must understand the basic teaching of this verse to be this: It is not man we must separate from, but man’s sin. On the one hand, there must be no sin in the church; on the other hand, there must be no disunity or conflict. We must try to persuade the sinner and the false teacher to repent; only if they refuse to repent are we to discipline them or separate from them. And whatever we do, we must do it in love and humility and under the direction of the Holy Spirit.
18 Paul here quotes from 2 Samuel 7:14. If we remain pure, God will be a Father to us, and we will be His children.