With us is the substance, with you the shadow only. Even as in your world they learn most who are most teachable, so in intercourse with ours. We can teach, if you are willing to learn. The merit of obedience and humility. So he best grows in knowledge.
All truth is mixed with error.
The dross will be purged away. All spirits teach differently. It is not so. We teach independently, and so details vary while the broad outline remains the same. You will know one day that evil, as you call it, is but the reverse of good.