When Did Preaching Become Profession?

I have a history degree and a Doctorate of Jurisprudence.  I am a published Christian author by Moody and have chaired a national Christian non-profit.  But I didn’t go to bible college or seminary.  Does that preclude me from preaching?

In the past several years I have felt an increasing call to perhaps move into preaching.  Those that I have mentioned it to have said, “But you didn’t go to seminary?  You are not ordained.”

Disheartened I have frequently just accepted the response sheepishly.

I continue to come back to the idea and wonder to myself, “When did preaching become a profession for which school, rather than God, qualifies you?”