"To change the nature of the individual (he wrote), to get at the heart, to save his soul is the only real, lasting method of doing him any good. In many modern schemes of social regeneration, it is forgotten that it takes a soul to move a body, e’en to a cleaner sty and at the risk of being misunderstood and misinterpreted, I must assert in the most unqualified way that it is primarily and mainly for the sake of saving the soul that I seek the salvation of the body. But what is the use of preaching the gospel to men whose whole attention is concentrated upon a mad, desperate struggle to keep themselves alive? You might as well give a tract to a shipwrecked sailor who is battling with the surf which has drowned his comrades and threatens to drown him. He will not listen to you. Nay, he cannot hear you, anymore than the man whose head is underwater can listen to a sermon. The first thing to do is to get him at least a footing on firm ground and to give him room to live. The you may have a chance. At present you have none. And you will have all the better opportunity to find a way to his heart. If he comes to know that it was you who pulled him out of the horrible pit and the miry clay in which he was sinking to perdition." William Booth
So, what more could I say? Just my take on it...
1. Social work is not salvation, but it is a logical and essential tool along the way.
2. If people haven't experienced salvation in any earthly sense, how could you expect them to experience in a Kingdom sense? It is like trying to teach children maths without first showing them numbers.
3. Real and long lasting change must therefore strive to be holistic, including both the body and the soul. Does this mean there is no salvation without social help? No, though the odds and lasting results would be interesting to see. And does it mean we only help others to evangelise? No, that would be kind of manipulative and shallow. Socail help and evangelism go hand in hand. If you don't believe me...read the Bible!
Hope this is helpful...