Shall not doubt in his heart (mh diakriqh en th kardiai autou). First aorist passive subjunctive with o an. The verb means a divided judgment (dia from duo, two, and krinw, to judge). Wavering doubt. Not a single act of doubt (diakriqh), but continued faith (pisteuh). Cometh to pass (ginetai). Futuristic present middle indicative.