Moksa Opadesa Yoga: Bhagavad Gita Chapter 18 [Final Revelations of the Ultimate Truth]
Krishna Said > Shaloka: 6
All these activities should be performed without any expectation of result. They should be performed as a matter of duty, O son of Prtha. That is My final opinion.
Although all sacrifices are purifying, one should not expect any result by such performances. In other words, all sacrifices which are meant for material advancement in life should be given up, but sacrifices that purify one’s existence and elevate one to the spiritual plane should not be stopped. Everything that leads to Krishna consciousness must be encouraged. In the Srimad-Bhagavatam also it is said that any activity which leads to devotional service to the Lord should be accepted. That is the highest criterion of religion. A devotee of the Lord should accept any kind of work, sacrifice or charity which will help him in the discharge of devotional service to the Lord.