The apostle Paul gives Christians several reasons in 2 Corinthians 3-5 why they are not to lose heart in the ministry:
1. Because God has made them sufficient to be “ministers of the new covenant” ministry through His Spirit which “gives life” in contrast to “the letter” of the Law which “kills” (3:5-6).
2. Because God has given them a ministry in which God’s Spirit transforms peoples’ lives from the inside out through His written word (3:15-18) and removes Satanic barriers that keep people from believing the gospel (4:1-6).
3. Because God has placed “this treasure” of the gospel “in earthen vessels” (frail bodies of believers) in order to show the “power” of His “grace” working in and through their sufferings and service (4:7-12).
4. Because God has given them the hope of sharing in Jesus’ resurrection (“He who raised up the Lord Jesus will also raise us up with Jesus”) in the future (4:13-15).
5. Because even though their physical bodies are deteriorating through the aging process and sufferings (“our outward man is perishing”), their inward spiritual lives are still developing (“the inward man is being renewed day by day”) by God’s grace (4:16).
6. Because their sufferings (“our light affliction, which is but for a moment”) for Christ’s sake, result in “a far more exceeding and eternal weight of glory” (eternal rewards) in the future (4:17).
7. Because their sufferings teach them to focus on what is “eternal” and “not seen,” rather than on what is “temporary” and “seen” (4:18).
8. Because all Christians who die will receive an immortal body (“we have a building from God…eternal in the heavens”) from the Lord (5:1).
9. Because all Christians possess “the Spirit as a guarantee” of their future immortal body in heaven (4:2-5).
10. Because death (“absent from the body”) begins a new existence for Christians in the presence of the Lord Jesus in heaven (“present with the Lord”) that is far superior to their present existence on earth (5:6-8).
11. Because ministry is about being “well pleasing” to the Lord who is realistic in His expectations of His children, not people who tend to be unrealistic in their expectations of others (5:9).
12. Because “all” Christians will “appear before the judgment seat of Christ” to receive rewards from Christ on the basis of their works (“according to what he has done”) for Him in the ministry (5:10).