Explanation:

Apart from this purpose of association [1], some other purposes are also accomplished. One such purpose can be mentioned here for example. God comes in human form due to the intensive prayers of devotees, to receive direct service from the devotees. As said above, God fulfills this desire of devotees by forcing the liberated soul to become inert energy and creating a forced deep sleep of the liberated soul even in the waking state of the human incarnation. Now God alone is left in the inert gross body and the human incarnation is still in the waking state due to the awareness of God. By this exceptional waking state, God alone receives the service of devotees by pervading all over the gross body. Thus, God fulfills the desire of devotees, which is to directly serve God alone. This special waking state of the human incarnation is well-explained above. But after sometime, the devotees develop negligence towards God due to continuous association. The gross body always bears the stamp of the liberated soul alone. The influence of the gross body and the negligence towards God gradually develops repulsion towards the human incarnation in course of time. This is simply human psychology as witnessed even in Pravritti[2]. In Pravritti, a new son-in-law is well-respected, but in course of time, he is neglected. This is the inherent nature of human beings. Based on this, in course of time, some devotees may even insult the human incarnation. We can quote an example here: Satyabhama knew very well that Krishna was God. But in course of time, she developed negligence based on the natural human psychology, due to the close and constant association with Krishna. Once, she hit Krishna on the head with her foot. This means that she hit God with her foot and this is the greatest sin, which has the highest eternal punishment. The deity of justice, being the loyal servant of God cannot tolerate this even though God may not mind it. If such an insult is not punished, the deity of justice will be deeply pained and God cannot neglect this either. To avoid this complication, God saves the insulting devotee from such danger by withdrawing Himself in to the heart[3] in a very minute state. The liberated soul takes over the ownership of the gross body and receives the insult. The liberated soul acts like the bodyguard of a minister by covering the minister when somebody shoots. The same sin committed towards a co-soul has temporary and relatively minor punishment, according to the constitution. If the liberated soul were absent from the gross body, this protective arrangement becomes impossible. In that case, the insulted gross body would belong to God alone; since the liberated soul is absent. Thus, God Himself would receive the insult and the punishment would be most severe. This is another purpose of association of God with a liberated soul to save the devotees from such an occasional slip.

[1] Giving the liberated soul the closest association with God and giving him the credit of Godhood.

[2] Worldly life

[3] heart of the liberated soul