I wouldn't put it that way.
1) I realize I do not know everything, and Cora has access to more info than I.
2) I'll never fully agree with anyone, and don't need to do so to "fully believe" in a baseball manager.
3) I may be the only poster who believes Cora is the best we ever had, so if I don't fully believe, I can probably still claim I "believe" in him more than anyone else here.