If Vaishnavism is so popular and wide spread in India, the credit must go to Sri Ramanuja, who took advantage of the ecstatic outpouring of the south Indian mystics, the Alvars, and produced a highly logical philosophy of knowledge soaked in devotion as the easiest means of God-realization.
The disciple must have great power of endurance. Life seems comfortable; and you find the mind behaves well when everything is going well with you. But if something goes wrong, your mind loses its balance. That is not good. Bear all evil and misery without one murmur of hurt, without one thought of unhappiness, resistance, remedy, or retaliation. That is true endurance; and that you must acquire.
-Swami Vivekananda