In man, one form of sacrifice is self-restraint. For example, on the plane of mind we should refrain from negative thoughts which, when released, will affect others more inclined to vice. Our duty is to plant wholesome seeds in the thought worlds. Such restraint, as we revamp our thought life, leads to a focus on liberation for others, not for oneself alone. This is a debt which, if left unpaid during life, leaves us spiritually insolvent and moral bankrupts in our next incarnation.
Theosophy is the quintessence of duty .
And while it is our duty to help all, that doesn't mean running around aimlessly, but helping those nearest us. Duty is a performance of that which presents itself, not just what we would like to do. This is the yoga factor. We need not go around long-faced with solemn countenance, or condemn the pleasures of those who cling to them. A constant account of all we must do can only bore our family and friends.