Answer:
The Old Testament tends to portray God as a wrathful, pro-war, vengeful, punitive, emotional entity. However, there could be many reasons for this: "people" (souls trapped in the physical universe by the "body", made of physical matter") perceived God in this way, because of fear. Fear inspired by their own choice to act against Him, not to intentionally disobey, but because they were "newborns" to the temptations of earthly influences (pleasures, sensations, etc.); perhaps God "appeared" harsh just as a new teacher knows that the first few weeks establishes who's in control - the teacher, or the class - therefore, seem very harsh at first; lastly, what we read in the Bible is the telling of experiences by MEN (human beings), who are emotional creatures, by nature.
What I would ask, instead, is "How long must people suffer" the consequences of separating themselves from God? And the answer to that is: As long as it takes for each soul to find his/her way back to God, if that is their Will. And to accomplish that, we must (individually) overcome our sinful natures, exemplified by lust, greed, pride, etc...as well as judging others or that which we do no understand, or know; to treat others as we would want to be treated; to choose to act upon our innate goodness, which so many of us do not do, for fear of judgement by others. One can only fear this, if they themselves judge others.
This is why Jesus sacrificed his life for us: to show us the way out of "Hell", which is a state of mind based upon believing and acting on selfish traits we've not yet overcome. Thus, his primary lesson - "Know Thyself", is a powerful lesson, for it is only when we can accept our shortcomings (as well as our spiritual growth and accomplishments) that enable us to perceive people in a nonjudgmental way, for each of us are guilty of sinning. It doesn't matter how; simply that we have no right to judge another for their sins, just as we do not want to be judged for ours.
The longer we continue to focus on others' selfish/sinful natures (or that which is perceived by us as selfish/sinful), we waste time tending to our own faults, and the desire to serve humanity by setting a good example to follow - to inspire people rather than tear them down.
THAT is when we will stop suffering.