It is the spiritual person who will attain in time immortality. He does not need to study much to prove to himself that he is spirit, for study will never convince him. It is the spirit itself which must realize itself. The soul is its own evidence, nothing else will make the soul realize its own being. The whole work of the Sufi, which he calls inner cult, is towards soul-realization. It is realized by rising above matter, and yet the condition is that one can only realize it by getting through matter.