Albert Barnes Commentary John 15:8

"Herein is my Father glorified, that ye bear much fruit; and [so] shall ye be my disciples." — John 15:8 (ASV)

In this. In this—that is, in your bearing much fruit.

Glorified. Honored.

Bear much fruit. Are fruitful in good works; are faithful, zealous, humble, devoted, always abounding in the work of the Lord. This honors God,

1. Because it shows the excellence of His law which requires it.
2. Because it shows the power of His gospel, and of that grace which can overcome the evil inclinations of the heart and produce it.
3. Because the Christian is restored to the Divine image, and it shows how excellent is the character after which they are formed. They imitate God, and the world sees that the whole tendency of the Divine administration and character is to make humanity holy; to produce in us that which is lovely, and true, and honest, and of good report. (Philippians 4:8).

So. That is, in doing this.

Shall you be My disciples. This is a true test of character. It is not by profession, but it is by a holy life, that the character is tried. This is a test which it is easy to apply, and one which decides the case. It is worthy of remark that the Savior says that those who bear much fruit are they who are His disciples.

The design and tendency of His religion is to excite people to do much good, and to call forth all their strength, and time, and talents in the work for which the Savior laid down His life. Nor should anyone take comfort in the belief that he is a Christian who does not aim to do much good, and who does not devote to God all that he has in an honest effort to glorify His name, and to benefit a dying world. The apostles obeyed this command of the Savior, and went forth preaching the gospel everywhere, and aiming to bring all people to the knowledge of the truth. It is this spirit only, manifested in a proper manner, which can constitute any certain evidence of piety.