I’m unsure as to how unconventional my view of altruism is among Christians but, for me, when I logically attempt to derive a conclusion as to whether the phenomenon truly exists, I only ever come to one answer. I should be clear that when I talk about altruism here, I am referring to the idea of complete selflessness; an ability to ultimately and definitively put someone else’s needs above one’s own.
Many people, certainly Christians, see Jesus Christ as the epitome of altruism, having come to Earth to take responsibility for all sin that ever was and ever will be, voluntarily suffering an excruciatingly painful death upon a cross for crimes he had never committed. It is perhaps the obvious decision to look at this act as one of true selflessness, but to do so implies that Jesus had no personal motive. Without believing that he had made the wrong decision, Jesus had satisfied a moral disposition within himself by choosing to die the way that he did. Had he made the opposite decision, he would have undoubtedly felt worse about the situation, being separated from far more of the people he loved and displeasing his Father, who is righteousness. Jesus, arguably, made the decision for himself as much as he did for all of us.
The same applies to humans, you might think you’re a good person because, perhaps, you try your best not to hurt anyone in the decisions you make, but really you are similarly selfless to someone who goes out of their way to hurt people for their own enjoyment. In both cases a decision is made to do what the person feels best about within themselves. Moral satisfaction is a motivator like any other.
So you might make a decision to do something that makes people feel good rather than bad, and I’m not saying that’s a bad thing – more often than not I believe that’s the righteous thing, keep on doing it! – but you’ve done it for yourself as well. The best way to look at it is to think of a time when you’ve done something you’ve perceived to be selfless, and ask yourself of you would rather have done the opposite. Then think why not. And you have found your personal motivation.