Jamieson, Fausset and Brown on John 14:8-12

8-12. The substance of this passage is that the Son is the ordained and perfect manifestation of the Father, that His own word for this ought to His disciples to be enough; that if any doubts remained His works ought to remove them (see on Joh 10:37); but yet that these works of His were designed merely to aid weak faith, and would be repeated, nay exceeded, by His disciples, in virtue of the power He would confer on them after His departure. His miracles the apostles wrought, though wholly in His name and by His power, and the "greater" works--not in degree but in kind--were the conversion of thousands in a day, by His Spirit accompanying them.