Vaishnava Dharmashastra 95.16

95.16

yad duṣcaraṃ yad durāpaṃ yad dūraṃ yac ca duṣkaram
sarvaṃ tat tapasā sādhyaṃ tapo hi duratikramam //

This whole world of deities and of men has devotion for its root, devotion for its middle, devotion for its end, and is supported by devotion.
17, What is hard to follow, hard to reach, remote, or hard to do, all that may be accomplished by devotion; since there is nothing that may not be effected by devotion.