Albert Barnes on John 14:11

Believe me, &c. Believe my declarations that I am in the Father, &c. There were two grounds on which they might believe; one was his own testimony, the other was his works.

Or else. If credit is not given to my words, let there be to my miracles.

For the very works' sake. On account of the works; or, be convinced by the miracles themselves. Either his own testimony was sufficient to convince them, or the many miracles which he had wrought in healing the sick, raising the dead, &c.