Paul’s emphasis on the gifts of the Spirit (both in 1 Cor. 12 and in Rom. 12:3–8) is for the purpose of “building up the church” (1 Cor. 14:12; cf. 14:4, 5, 26, 31). But why does the church constantly need “upbuilding and encouragement and consolation” (v. 3) by means of the Spirit? 

The answer is simply that eschatological hope is difficult to maintain. 

People easily abandon the Parousia and the resurrection of the dead (whether explicitly by confession or implicitly by lifestyle and focus).The grind of mortality and the mundaneness of quotidian existence have a way of blunting vibrant faith. Moreover, biblical eschatology is literally unbelievable. Nothing about our world conveys that a divine being is coming with fire and angels to reverse history and radically transform the cosmos. It was just as impossible in Paul’s day as it is in our post-Enlightenment day. Thus, we need “signs and wonders” (Rom. 15:19; 2 Cor. 12:12; 2 Thess. 2:9) and the working of “miracles” (1 Cor. 12:10, 28f.; Gal. 3:5) to sustain hope in the Miracle. This is why Paul held vigorously to the gifts of the Spirit (even in their abuses at Corinth), because a lack of gifts tends toward a lack of eschatological faith. “Therefore you do not lack any spiritual gift as you eagerly wait for our Lord Jesus Christ to be revealed” (1 Cor. 1:7, NIV). - John P. Harrigan