The angel Gabriel is helping Mammon, the devil's son, cross over from hell into our plane (earth), to punish all humans... but just before she does so, Constantine slits his wrists to commit suicide and the devil Lucifer comes to take his soul back to hell. Lucifer then stops Gabriel from helping Mammon cross over, and takes Mammon back to hell.Constantine sacrifices himself to take the place of Angela's sister, who really committed suicide and is now in hell, so she can go to heaven. Because of this sacrifice, Constatine is about to go to heaven, but Lucifer heals his ailing lungs (from chain smoking) and Constantine lives again. Gabriel loses her wings, and becomes human herself.Staying after the credits reveals that Chaz (who is killed by Gabriel) has become an angelic half-breed.
andrejtu
Answer: Sin for a good reason is still sin, and as Gabriel says earlier, you can't buy your way into Heaven. Real Catholic dogma, however, doesn't hold the mentally ill as condemned for committing suicide.
Greg Dwyer
Except Isabel wasn't mentally ill. She saw angels and demons just like Constantine did. It was her parents who believed she was mentally ill.
While suicide is a mortal sin, it's shown later (as in major plot point) that sacrificing yourself to save the world is a redeeming act.
Yes, but Constantine also said "My parents were normal. They did what most parents would do. They made it worse. You think you're crazy long enough, you find a way out" which could relate to Isabel losing her sanity in a way as well because of her family and how they saw her. The whole Isabel's sacrifice is added by the novelization but the movie is ambiguous about the suicide.
mp1920
Except Isabel wasn't mentally ill. She saw half breeds just like John did.
Sacrificing yourself for others isn't a sin.