Actually, I don’t think that’s true, that belief in an afterlife excuses suffering in this one. Judaism, for example, is not in favor of suffering in this life. There’s a strong sentiment of improving your surroundings, friends, family, others, and self in a very material, make-the-best-of-being-alive, sense.

Conversations with Rabbi Small sort of lays out some of the philosophies I’m talking about
here.

I believe there are other religions that have similar outlooks. Belief in an afterlife doesn’t necessitate lack of interest in this life.

Finally, if Mother Theresa has the means to prevent loss-of-life or pain-and-suffering, and consciously chooses a path that favors conversion over alleviation of suffering.. than I’m not sure I like her so much any more. I can’t argue against her devoutness; she may be doing what she believes best for others. I can, however, argue against her (alleged) basis of comparison. It doesn’t square with my idea of what’s best for the needy.