One Hour of Teshuvah
TeshuvahTorah learning
The Mishnah says that one hour of teshuvah in this world is better than all of the World to Come. The Modzitzer Rebbe cites his grandfather, the Kuzhmirer, who explained that an hour of teshuvah in this world, filled with inhibitions, difficulties and delays, is more precious and beautiful to Hashem than the entire coming world. The World to Come is a place of rest, like a retreat tent, where there are no troubles or difficulties.
Source: Kelalei Oraisa, os yud (on Avos 4:17)