The Bhāgavata gives the definition of mukti: mukti hitvā anyathā rūpaṁ svarūpeṇa vyavasthitiḥ (SB 2.10.6). What is mukti? Mukti means when one gives up his engagement, activities, hitvā anyathā rūpam, identifying himself with something material, and he is engaged in his own original, constitutional position, and that is called mukti. The original constitutional position is every living entity is a part and parcel of the Supreme Person.
I have given you several times example—this is stated in the śāstras also—just like this finger is my part and parcel of this body. It is the duty of the finger to serve the whole body. I want to do like that, the finger helps me. That is the duty of the finger. If the finger cannot do it, then it is to be understood that he is diseased. It is diseased. As soon as the finger cannot give me regular service, it is to be understood that it is diseased. Similarly, any person who is not giving service to the Supreme Personality of Godhead, he is diseased, materially diseased. He has to be cured.