Even though in this world there is no external difference between someone who learns and someone who doesn’t, that is only because it is His will it should be so, that the reward should be concealed to allow people free choice. When Mashiach comes, and the spirit of desecration will dissipate, it will be externally apparent what spiritual level a person is on, and the Torah a person acquired will shine forth, each to the degree he achieved. As it says in Tana Devei Elyahu, ‘In the future Hashem will sit in His great Beis Medrash in Yerushalayim, and all the tzaddikim will sit before him, beaming with the Torah they learned.