I can only speak as a person raised Catholic (heh...), but let me present a wild scenario.

Could you imagine the actual Holy Spirit having a clear and direct sentient influence in your child's life?

With this connection to the Holy Spirit, he starts performing absolutely insane miracles that a Child shouldn't be capable of and by the age of 8 God's chosen priest shows up like "Hey kid, have you heard of our lord and savior Jesus Christ? In my day, he was super sexy. You’re special. I'm going to train you and later you should probably go to a religious school."

And then, by age 17ish, Jesus himself shows up like, "Yes, twas me the whole time. Let me train you one on one my child." And then a year later, your son tells you he's sleeping with Jesus?

Like...does this help anyone understand what happened to Gale better? Or does it help that the Mystra analog is depicted as a man? Do you need me to hold your hand and tell you that even if Gale showed interest, it was on Mystra, as the omniscient god with all the power in the relationship and Future sight?!, to not fucking sleep with the mortal who maybe became an adult 5 minutes ago?