"Whatever the salutary effects of this kingdom on the wider society due to Christians living as salt and light, this age cannot be saved. It is dying. Through his apostles, Christ declares to the churches, 'Grace to you and peace from God our Father and the Lord Jesus Christ, who gave himself for our sins to deliver us from the present evil age, according to the will of our God and Father, to whom be the glory forever and ever' (Gal. 1:3-5). To be sure, the Spirit is at work in common grace, restraining the spiritual entropy of this present evil age. However, the Spirit's saving mission is not to improve our lives in Adam, under the reign of sin and death, but to crucify us and raise us with Christ. Paul reminds us that 'the appointed time has grown very short' (1 Cor. 7:29). We marry, live, and work in the world, but without anxious attachment to this present age, 'for the present form of this world is passing away' (1 Cor. 7:31). Like God's counsel to the captives in Babylon, Peter exhorts believers to 'conduct yourselves with fear throughout the time of your exile, knowing that you were ransomed from the futile ways inherited from your forefathers, not with perishable things such as silver or gold, but with the precious blood of Christ' (1 Peter 1:17-19, emphasis added). Fully involved with the common life of our neighbors, we are nevertheless pilgrims who, with Abraham, are 'looking forward to the city that has foundations, whose designer and builder is God' (Heb. 11:10)" (The Gospel Commission: Recovering God's Strategy for Making Disciples, 70-71).
Pilgrims and exiles do not get too attached to their temporary home. "They desire a better country, that is, a heavenly one.
Therefore God is not ashamed to be called their God, for he has prepared for them a city" (Hebrews 11:16 ESV).