2. The stage of preparation
This stage is a continuation from the last. Even greater powers of reason and concentration are attained. Much deeper insight into the nature of Reality is developed and an ever improving mental picture of it. The extremes of positivism (things exist) and nihilism (nothing exists) are discarded, and with them the seeds of wrong views.
Towards the end of this stage one's powers of concentration and patience are so strong there is no chance of ever being "reborn" in any of the three lower realms (hells, pretas, animals). Such patience gives one enormous capacity to take-on suffering and to face one's fears. People who have little knowledge of suffering, like those in the deva realms, cannot attain the final part of this stage as it is too painful for them. They do not have the strong renunciation of a "human", who has less happiness to lose, and is more used to living with suffering and bearing-up under it.
With armour-like perseverance, great faith, and knowledge of Reality, a strong foundation is laid, and one now feels competent to attain full realization of Reality. The highest has been understood - but the highest is not to only understand it, but to realize it.