In the Vedas the rishis and munis had indicated four types of purushartha, four kinds of striving: dharma, artha, kama and moksha. Dharma means ‘virtues, qualities, good actions, good deeds’. Artha means ‘purpose, selfishness, motivation, objective’. Kama means, ‘desires and their fulfilment’. Moksha means ‘liberation from everything’, when the mind follows neither dharma nor artha nor kama. Now, these four purusharthas or strivings, must be integrated and synthesized together. For one who is a householder, artha and kama are prominent, and dharma and moksha are the internal, inherent qualities or inspirations.
For a karma sannyasin or a sannyasin, dharma and moksha are prominent qualities; artha and kama may go with him. This is how the synthesis has to be done. In fact, the Vedas have been emphasizing one single point: that one stage of life leads to another. Brahmacharya ashrama leads to grihastha ashrama, grihastha ashrama leads to vanaprastha ashrama and vanaprastha ashrama leads to sannyasa ashrama. It does not mean that you have to leave your home and do this or that. These are the automatic developments of the philosophy and the thought within your mind.
A karma sannyasin has to regard his involvement in life as an expression of his karma. Therefore, it forms a part of his dharma or duty. He must not overlook or negate it. Every experience can be utilized as a stepping stone to higher evolution. So, he lives as an ordinary householder, experiencing everything, but at the same time, using all his experiences to raise his awareness, thereby arriving at a state where he does not create any more karma.
A karma sannyasin is expressing his karma like anybody else, but because of his higher awareness, goal, dedication and proper understanding of life, he is able to free himself of karma, of the laws of cause and effect. At this point, he may renounce or do whatever he wishes, but until then he has to live his life and experience it fully as a karma sannyasin.