I mean "good" broadly speaking. That could mean anything. It seems like we are bombarded with people who live, at least overtly, moral lives but who are somehow fake. The word "result" reminds me of an English language translation of "karma".
I think that Kant said that a heaven was necessary to understand morality. And although this often is a motivating factor to being good, motivations can be mistaken.
Is moral behaviour without a future heaven futile? Some philosophers claim that we need an immortal soul in order to live a meaningful life:
Tolstoy argues that for life to be meaningful something must be worth doing, that nothing is worth doing if nothing one does will make a permanent difference to the world, and that doing so requires having an immortal, spiritual self...
Life seems nonsensical when the wicked flourish and the righteous suffer, at least supposing there is no other world in which these injustices will be rectified, whether by God or by Karma....
The best justification for thinking that one must have a soul in order for one's life to be significant seems to be that significance comes from uniting with God in a spiritual realm such as Heaven, a view espoused by Thomas Aquinas, Leo Tolstoy (1884), and contemporary religious thinkers (e.g., Craig 1994).
But maybe these philosophers aren't concerned with how the meaninglessness of all life might undermine morality.