"Spiritual enlightenment isn't all it's cracked up to be, is it."

He says this like he's speaking from personal experience which, in a certain sense, he is. He's seen spiritual enlightenment handed down to prophets and martyrs for ages by the angels, and it's all just agendas and propaganda. Getting done what they want done by the careful manipulation of these humans that they're supposed to be shepherding.

'Deeply meaningful' his feathery ass.

Lucifer has nothing but disdain for humanity, but at least he hasn't spun it to look like it's just a higher form of love.