The Soul's Nature
We souls are complete persons and don’t require the bodies we now inhabit. We have our own spiritual senses, mind, and intelligence. Our identities are unique, eternal, and unchanging, and can never be lost by merging with some homogeneous spiritual entity.
As spiritual beings, we are by constitution eternally happy and full of knowledge. Sadness, ignorance, and death are unnatural for us, and that’s why we struggle against those things in this world.
While God is infinite, we souls are small and are subordinate to Him. We exist to serve Him in love. Our intrinsic nature—our dharma—is to serve. That quality cannot be separated from us, just as heat cannot be separated from fire and sweetness cannot be separated from sugar. We will find full satisfaction only in re-discovering our unique service to God.
We have free will and some independence. We can choose to love and serve Krishna, or we can choose not to and can try to enjoy separately from Him in the material world. While in the material world, we can choose to take up spiritual practices that will re-awaken our love for Him.
More on this topic in Bodies and souls