According to the Bhagavad Gita, the second way to attain union with God is:

Explanation

A common presentation of the principal spiritual paths of the Bhagavad Gita lists Karma Yoga, Bhakti Yoga and Jnana Yoga—action, devotion and knowledge. In that conventional ordering, Bhakti is the second path. The paths are complementary approaches to spiritual union rather than a rigid ranking of higher and lower methods.