Why do the elect do good works?

Ephesians 2:8-10: For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast. For we are his workmanship, created in Christ Jesus for good works, which God prepared beforehand, that we should walk in them.

Titus 2:14: …[Jesus Christ], who gave himself for us to redeem us from all lawlessness and to purify for himself a people for his own possession who are zealous for good works.

In these two texts we see two great truths related to your question: (1) Christians are redeemed through Christ alone and not by their works, and (2) before the saints’ salvation in time God prepared his people to be zealous of good works “according to the purpose of his will and to the praise of his glorious grace” (Eph. 1:5-6). In the first, Paul says that God prepared his people — his possession — in advance that they would walk in good works (Eph. 2:10). He not only prepared them to do these works but, as seen in the second text, we are zealous to do them. Still, while good works are in part an evidence of one's salvation (Jas. 2:17-18), this doesn't mean that good works are the cause or basis for the same.

God makes us his own through Christ alone. As God's people, we are given a new life, love, mission, and works. As new creations in Christ, we are zealous to do good works; that is we are enthusiastically devoted to their performance. Being free in Christ allows us to express our love for God through these works. This is part and parcel of continuing God's now-but-not-yet kingdom upon this earth. There is a sense of an urgency to these works because we understand in some measure that the days are short before our Lord's return and the consummation of his kingdom.

But the Great Shepherd won't be coming back until everyone of his elect are brought into his sheepfold (cf. Matt. 18:12-14; Luke 15:3-7). The fields are ripe for harvest (John 4:35). God's elect are scattered among every nation, among all tribes and peoples and language (cf. Rev. 5:9; 7:9). Some possibly haven't even been born yet and gospel preparations must be made for them as well. So Christ, the Lord of the harvest (Matt. 9:37-38), sends us to help gather the elect from the four winds of the earth (cf. Matt. 28:18-20; Mark 13:27). We do this zealously through prayer, sharing his word and sacraments, feeding the hungry, visiting the sick and those in prison, etc. (cf. Matt. 25:35-36; 28:18-20). Some call this mission and evangelism. As kingdom sons and daughters, it is our privilege and joy to share the great love that God has already given to us (cf. Rom. 5:8). Christ's love compels us (2 Cor. 5:14; cf. Acts 18:15; Rom. 5:15; Gal. 2:20; Col. 3:3).

Yes, those in Christ joyfully work in Christ's field — this earth. We don't do it to earn salvation, but it is a definite byproduct of us being redeemed by the Lord. Christ loves us. He has changed us. He has and is still equipping us. He has given us his mission to live out. What a joy and privilege to do his good works.

Christians who do not have the joy and zeal in doing their Lord's work should seriously reconsider his words in Matthew 25:41-46.