Rav Riechman spoke about how the first three galuyot each attacked the Jews on only one plane of existance : physical, emotional, or intellectual. Hoever, the last galus- of Edom that we are in now, combines that attack at all levels.
In the past Rav Riechman has spoken about how important challenges are for spiritual growth. If we were challenged on each level seperately then we had to work to strengthen ourselves spiritually on that level.
I wonder if once we went through all the first three we were strengthened in each of these things, but that's not enough. A person is a multi-dimensional being. (Unlike angels who are only one dimensional and purely spiritual.) It's not enough to be stong in each level seperately, but rather we have to make sure to have all these elements integrated into our total personality. Maybe that's why we still need this last galus, which attacks us on things we have already worked on - yet not all together. In this galus we must work at combining our physical, emotional, and intellectual sides. Kedusha is not about denying one aspect of the self, but rather about integrating even the lowest physical level into avodas Hashem. In this galus, if we are successful in meeting the challenge then we will be much higher than we were before, by integrating all these aspects into a total life of kedusha.