John Wesley on Acts 20:32

The word of his grace - It is the grand channel of it, to believers as well as unbelievers. Who is able to build you up - To confirm and increase your faith, love, holiness. God can thus build us up, without any instrument. But he does build us up by them. O beware of dreaming that you have less need of human teachers after you know Christ than before! And to give you an inheritance - Of eternal glory, among them that are sanctified - And so made meet for it. A large number of these Paul doubtless knew, and remembered before God.