Q. How should one learn to accept happiness and sufferings equally? What does rapid sufferings of an initial beginner in spiritual path indicate? Does God give material benefits to a neophyte or does he give rapid sufferings to test him?
A. In Bhagavad Gita (5.15) Krishna says that, ‘Embodied beings, however are bewildered because of the ignorance which covers their real knowledge.’ Being in a bewildered condition therefore, the embodied soul identifies himself with the circumstantial material body and becomes subjected to the temporary misery and happiness of life. Real knowledge is our understanding of our relationship to Krishna and attempting to re-establish it. With such knowledge one becomes equipoise without any attachment to success or failure.
Regarding your point about ‘rapid sufferings,’ Srila Rupa Goswami mentions in the Nectar of Devotion that ‘bhakti is klesaghni subhada,’ that it provides immediate relief from material distress. Srila Prabhupada gives the analogy of a fan that continues to rotate even after the plug is pulled out. Similarly, one may suffer from past reactions in the early stages of bhakti but gradually this will also cease.
With respect to the third part of your question, Krishna reciprocates according to the desires and advancement of the devotee. He gave unlimited opulence to Sudama and put Queen Kunti into so much distress, both very dear devotees and in both cases the end result was bringing them closer to Him.