There are few school of thoughts. One say that enlightenment might be achieved through joy and another one says-suffering. I'm unfamiliar with both, but historically - Buddha and Christ came to help those who suffer. We all suffer same sufferings. Krishna came when Arjuna faced a tough decision. I guess the joy comes only to those who TRULY believe, and the faith raise them above all the suffering and compassion, etc. Have you seen joy in scriptures?