Atmakarma must be practiced with an undivided devotion...

 “Atmakarma (Kriya Yoga) must be practiced with an undivided devotion and a true divine spiritual motive (Bhava). Many Kriya Yoga practitioners have achieved self realization through the devoted practice of Atmakarma. It should be noted that if Atmakarma is practiced without unconditional devotion and without true dedication and or in a mechanical way (like a machine), the desired results (effects) will not occur.”

— Lahiri Mahasaya, Aryya Mission Gita p.38