Answer by A Quora admin:
Altruism: the principle or practice of unselfish concern for or devotion to the welfare of others (opposed to).
Proselytizing ('giving them the Gospel') may be a religious virtue but altruism is not.
Because of the definition's operative word: UNSELFISH.
Proselytizing doesn't cost anybody anything. Therefore (un)selfishness never enters the picture in any way, shape or form.
However, if the gospel leads you to help the needy at a cost to yourself (and without proselytizing), then that would be altruistic.