(Eruvin 41b) "Someone who has a bad wife will not see Gehinom"
What does this mean exactly?
The context is as follows:
ג' אין רואין פני גיהנם אלו הן דקדוקי עניות וחולי מעיין והרשות ויש אומרים אף מי שיש לו אשה רעה ואידך אשה רעה מצוה לגרשה ואידך זימנין דכתובתה מרובה אי נמי אית ליה בנים מינה ולא מצי מגרש לה למאי נפקא מינה לקבולי מאהבה
Three kinds of person do not see the face of Gehenna, viz., [one who suffers from] oppressive poverty, one who is afflicted with bowel diseases, and [one who is in the hands of] the [Roman] government and some say: Also he who has a bad wife. And the other? — It is a duty to divorce a bad wife. And the other? — It may sometimes happen that her kethubah amounts to a large sum, or else, that he has children from her and is, therefore, unable to divorce her. In what practical respect does this matter? — In respect of receiving [these afflictions] lovingly.
From the context, it is clear that the "bad wife" is one who causes him suffering, just as the other three instances are of suffering. And these afflictions atone for any sins which would otherwise require Gehinnom.
The Talmud is acknowledging that some problems we can fix, and some we can't. We value commitment, not suffering for its own sake. If a problem can be fixed, we should do so. But sometimes a person can be in an awful situation where all we can do is tell them that they've lived through so much suffering, there's no need for Hell afterwards.