Question
Is Life after Moksha possible?
Answer
No. It's not possible.
After Moksha, a soul has become God by merging into the singularity of God. What God does, that soul does or what that soul does, the God does. Both are same.
The question rather should be,
Is it required to have a life after Moksha?
A soul with no desire left and who has conquered its Rajo-Guna (the mode of passion) will not have anything to do with the material world. Even that soul doesn't have to guide anyone, because tendency to guide or help is also a (selfless) desire.
All the entity come to manifested from unmanifested when the day of Brahma starts. Unmanifested is the actual nature of God, which is Nirguna (mode-less), Nirvikara (distorion-less) and Nirpeksha (non-relative). However with its own Yoga-maya, the unmanifested God can also take a manifested form of soul, superior than the others.
Presumably, your question is about the regular souls like us. When such soul realizes the God, it finally merges within the God's unmanifested form. It's like a water droplet merging into the ocean.
Can we say that when a new body is formed later, the same droplet is again attached? We can safely assume that it's gone for good!
But those who worship Me, giving up all their activities unto Me and being devoted to Me without deviation, engaged in devotional service and always meditating upon Me, having fixed their minds upon Me, O son of Pṛthā – for them I am the swift deliverer from the ocean of birth and death.
One who understands this philosophy concerning material nature, the living entity and the interaction of the modes of nature is sure to attain liberation. He will not take birth here again, regardless of his present position.
The souls which are going to attain Moksha would enjoy within the present life as well:
When the embodied being is able to transcend these three modes associated with the material body, he can become free from birth, death, old age and their distresses and can enjoy nectar even in this life.
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