The easiest way to attain God is through the science of God.

Easy path to attain god is called as sahaj marg in the ancient philosophy. Without the Science of God (Brahma gyan) and knowledge of god (Brahma Vidya), attainment of God is not possible.

— ancient philosophy. 

Is the science of god possible through devotion?

Knowledge is possible through devotion, meditation through knowledge, and Brahma knowledge is possible through meditation.