Ben Thomas did a lot of very good and commendable deeds, but all for the wrong reason. You totally understand his remorse and depression, and you could almost say that his death did bring about some good. However, understanding the purpose of our life here on earth and God's eternal plan for his children, blesses us with the knowledge that this life isn't it.
[***Spoiler Alert***] Ben's theft of his brother's IRS credentials doesn't really make his deeds 100% good, he committed a very serious offense to help supress his own guilt. His relationship with Emily was portrayed as something that was good. However as the story reaches it's climax the director disappoints us by portraying Ben and Emily's last act together as something that illustrates true love. In reality, and it doesn't take much experience to realize this, there is more to love than just a physical relationship.
In Ben's mind he was trying to do as much as possible to make up for the seven deaths he caused by giving his own body and material belongings to help improve the lives of others, but with an eternal perspective it is selfish and erroneous to think that taking your own life (no matter what you do with it) will make anything or anyone better. The overall message appears to be that even something inherently wrong is ok if it ends up helping others...which is not true especially since it culminates in one more life that he took. No matter how many good deeds we do, it does not erase our sins or mistakes. And while serving others can help cure depression, taking a life (whether your own or someone elses) actually worsens your state for the next life.
But, because Ben didn't have this eternal perspective and didn't seem likely to be in a position to acquire it, maybe enriching seven other lives and ridding the world of his depressed, guilt-ridden self was the best thing to do. Maybe what he did prescribed to a higher level of ethics and that what was not legal was actually what was in the best interest of everyone.
Either way I did not feel good after the movie, nor inspired to donate my organs.