Profane energy was a dark, all consuming energy that ate and absorbed everything into itself, able to corrupt and destroy everything. In comparison, divine energy was a purer energy that could transform into any other kind of energy it needed to be, and accomplish miracles.
In theory, both energies could not be casually wielded and required very specific circumstances, or beings to be able to control. Lex was already beginning to learn about laws, though he hadn't technically spent any proper time contemplating it. The next thing he needed to understand were energies.
Different energies enabled different things, and using the right kind of energy in the right circumstances would produce a greater effect.