I think these questions are relevent and that their answers are knowable and I've come across several ideas that I find provacative.
One is the image of Spirit as a Spark of the Divine. That is, Spirit is a creation (a gift or a birthing process) of Life. That Life (God) is the primal force of the Universe, that Life's nature is creative, and that the energy of creation is Love. So our Spirit is a expression of love by Life - and that being made in God's image and in Essense the same, it's also our nature to create or manifest as an expression of Love.
Another idea is similar to the concept of AI (artificial intelligence) - that the Mind/Spirit is a consequence of a complex organism. In this idea Mind/Spirit is a type of awareness resulting from incredibly complex chemical and electrical systems. That this awareness is a form of energy that has the potential to be developed, refined, and evolved beyond the body.
The first idea seems more poetic and beautiful and I enjoy it deeply on that level. The second idea is interesting in that it's an extension of the idea of evolution.
But I think these questions are relevent beyond the level of intrigueing curiosites. I believe they are relevent to the realization of our full capacity as beings.