I think this is one of the most important articles to read in preparation for Rosh Hashana: Why Judgement – By Rabbi Noson Weisz
INVESTMENTS VERSUS REWARDS
The very first point that must be emphasized is that contrary to popular belief, Rosh Hashana is not about reward and punishment. The Talmud informs us that mitzvot cannot be rewarded in this world (Kiddushin 39b). The commentators explain that the physical world simply does not have the resources to deliver the amount of joy required to compensate the performance of even a single Mitzvah.
Only people who do not have the merit to make it to the World to Come are written into the Book of Life to compensate them for their past good deeds; we certainly hope that none of us are in this position, The conclusion: when we stand before God and pray for a good life in the coming year, we are not asking Him to provide it fo rus as a reward.
But if the judgment we face on Rosh Hashana does not concern reward, what exactly is being weighed? According to Rabbi Dessler, the model we should study as an aid to understanding the deliberations of the Heavenly Court on Rosh Hashana is an economic investment model; the judgments of Rosh Hashana are the heavenly equivalents of earthly investment policy decisions. On Rosh Hashana it is decided how much Divine energy God will invest in the world in general and in our own lives in particular in the course of the coming year.
Please read the whole thing.