If we're going to be brutally honest, the only reason many Christians do anything 'for God' is ultimately out of a desire for their own security, or their own salvation, or their own avoidance of hell, or for their own good standing with the creator, or to be looked fondly upon by God. I mean, really, preachers preach 'repent and you will be saved', and it's that thought of reward or of avoidance of punishment that drives most if not all Christian people.
This woman's being more truthful about the idiosyncrasy of 'selflessness' for an ultimately selfish end than I've seen much of in a lot of religious circles. When we really examine it, there's always an end reward for 'me' in sight that ultimately justifies adherence to the dictum, however counter-intuitive that dictum may really feel to the adherent.
There are of course, the exceptions, who recognize the benefit of living lives in a certain manner, and have more profound motives for faith; the pursuance of peace, the cause of others, if only for the cause's own sake.