Srila Prabhupada - Vedic Teachings

  "The Supreme Lord is cognizant and all-powerful, and by His causeless mercy He empowers a living entity to receive His mercy. Being under the spell of conditional life, people in general are averse to rendering devotional service and practicing Kṛṣṇa consciousness. In fact, most people are unaware of the principal teachings of Kṛṣṇa consciousness regarding one's eternal relationship with the Supreme Personality of Godhead and the ultimate goal of life, which is to return home, back to Godhead. Nor are people aware of the process by which one can return to the spiritual world. Because these important subject matters are unknown to the conditioned soul, Lord Caitanya, out of His causeless mercy, instructed Rūpa Gosvāmī in the principles of devotional service. Later, for the good of the people in general, Rūpa Gosvāmī distributed this information of the science of devotional service.” (Teachings of Lord Caitanya,  TLC 1: Teachings to Rupa Gosvami )

  "There is no mechanical process to see the form of the Lord. It completely depends on the causeless mercy of the Lord. We cannot demand the Lord to be present before our vision, just as we cannot demand the sun to rise whenever we like. The sun rises out of his own accord; so also the Lord is pleased to be present out of His causeless mercy. One should simply await the opportune moment and go on discharging his prescribed duty in devotional service of the Lord. Nārada Muni thought that the Lord could be seen again by the same mechanical process which was successful in the first attempt, but in spite of his utmost endeavor he could not make the second attempt successful. The Lord is completely independent of all obligations. He can simply be bound up by the tie of unalloyed devotion. Nor is He visible or perceivable by our material senses. When He pleases, being satisfied with the sincere attempt of devotional service depending completely on the mercy of the Lord, then He may be ...