Cosmology
Abel is the prototype of a heavenly authority and priesthood at the communal level. He is concerned with spiritual matters and the higher meaning of reality. Cain is the prototype of earthly power and kinghood at the communal level, concerned with possessing the land and dealing with its practical realities.
God accepts the offering of Abel rather than Cain because one is higher than the other in the vertical space of this cosmology (Intangible Meaning - Spiritual – Animal – Vegetable – Mineral – Meaningless Matter).
In a perfect world, Cain and Abel would reach an agreement by which spiritual and material realities would have been joined correctly. Abel would cover Cain with spiritual meaning from heaven, and Cain would support Abel with physical power from the earth. Authority and power did not reach an agreement, though.
(The Language of Creation: Cosmic Symbolism in Genesis - A Commentary by Matthieu Pageau, 2018. Pages 89-92)