This is a very helpful article by Tim Keller on The Gospel and the Poor. Here is the introduction:
The original question I was asked to address was “How does our commitment to the primacy of the gospel tie into our obligation to do good to all, especially those of the household of faith, to serve as salt and light in the world, to do good to the city?” I will divide this question into two parts: (1) If we are committed to the primacy of the gospel, does the gospel itself serve as the basis and motivation for ministry to the poor? (2) If so, how then does that ministry relate to the proclamation of the gospel?
And here’s some of what Keller has to say on the relationship between evangelism and the preaching of the gospel:
(1) Evangelism is distinct.
The modernist church of the early twentieth century reduced gospel ministry to social ethics and social action. The quaint saying “preach the gospel; use words if necessary” fits in with this idea that the gospel is basically “a way of life” and that gospel ministry is “making a better world.” But this not only contradicts the Bible’s teaching that the gospel must be verbally proclaimed and responded to in repentance and faith. It essentially denies the gospel of grace through God’s saving acts in history and replaces it with good works and moral improvement.
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(2) Evangelism is more basic than ministry to the poor.
Evangelism has to be seen as the “leading edge” of a church’s ministry in the world. It must be given a priority in the church’s ministry. It stands to reason that, while saving a lost soul and feeding a hungry stomach are both acts of love, one has an infinitely greater effect than the other. In 2 Cor 4:16–18, Paul speaks of the importance of strengthening the “inner man” even as the outer, physical nature is aging and decaying. Evangelism is the most basic and radical ministry possible to a human being. This is true, not because the “spiritual” is more important than the physical (we must be careful not to fall into a Greek-style dualism!), but because the eternal is more important than the temporal (Matt 11:1–6; John 17:18; 1 John 3:17–18).
(3) But ministry to the poor is inseparably connected to evangelism.
We all know the dictum: “we are saved by faith alone, but not by faith that is alone.” Faith is what saves us, and yet faith is inseparably connected with good works. We saw in Jas 2 that this is also the case with the gospel of justification by faith and mercy to the poor. The gospel of justification has the priority; it is what saves us. But just as good works are inseparable from faith in the life of the believer, so caring for the poor is inseparable from the work of evangelism and the ministry of the Word. In Jesus’ ministry, healing the sick and feeding the hungry was inseparable from evangelism (John 9:1–7, 35–41). His miracles were not simply naked displays of power designed to prove his supernatural status, but were signs of the coming kingdom (Matt 11:2–5.).
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(4) Inseparable does not mean a rigid, temporal order.
What do we mean by “inseparable”? Ministry to the poor may precede the sharing of the gospel as in Jesus’ ministry to the blind man. Though the deed-ministry led to the blind man’s spiritual illumination, there is no indication that Jesus gave the aid conditionally. He did not press him to believe as he healed him; he just told him to “go and wash” (John 9:7). Even so when Jesus spoke of giving money and clothing to those who ask, he insisted that we should give without expecting anything in return (Luke 6:32–35). We should not give aid only because the person is open to the gospel, nor should we withdraw it if he or she does not become spiritually receptive. However, it should always be clear that the motivation for our aid is our Christian faith, and pains should be taken to find non-artificial and non-exploitative ways to keep ministries of the Word and gatherings for teaching and fellowship closely connected to ministries of aid.