Patañjali's Yogasūtra I.29

Yogasūtra I.29 - tataḥ pratyak-cetanā-adhigamaḥ api-antarāya-abhāvaḥ-ca

For those who have faith in God, and who have successfully mastered Mantra-japa,

The individual will in time perceive his/her own true nature. He will not be disturbed by any obstacles that may arise in his journey towards the state of Yoga.