One's natural tendency is to serve because a living entity is an eternal servant of God. The living entity wants to serve, but because of his forgetfulness of his relationship with the Supreme Lord, he serves under the modes of material nature and manufactures various modes of service, such as socialism, humanitarianism and altruism. However, one should be enlightened in the tenets of Bhagavad-gita and accept the instruction of the Supreme Personality of Godhead that one give up all natural tendencies for material service under different names and take to the service of the Lord. One's original natural tendency is to act in Krsna consciousness because one's real nature is spiritual. The duty of a human being is to understand that since he is essentially spirit, he must abide by the spiritual tendency and not be carried away by material tendencies.

>>> Ref. VedaBase => SB 6.1.53