That we should be to the praise of his glory, who first trusted in Christ.
In order to understand this sentence, we must consider that the term, "trusted in Christ," implies more than it expresses; even the coming to God, or repentance, through belief, or hope, or trust that Christ, by His death, has made reconciliation with God for all who will come to Him in this hope, belief, and trust. The sentence, then, must be understood as thus: "That we should be to the praise of His glory, who first drew near unto Him, through trust in the reconciliation which Christ has made"; and then we see how this is to the praise and glory of God. For God's glory is manifested by the exercise of His gracious attributes of mercy and loving kindness and forgiveness; but these He is prevented from exercising towards men when their hearts are impenitent and unbelieving, as we find it recorded of our Lord, that "He could there do no mighty works, because of their unbelief." But what does the apostle mean when he speaks: "we who first trusted in Christ"? He is speaking apparently of the Jews, the first to whom the gospel was preached; as we find our Lord instructing His apostles, "Go not into the way of the Gentiles, and into any city of the Samaritans enter ye not, but go rather to the lost sheep of the house of Israel"; and again, we have St. Paul saying that the offer and promise of salvation was made to the Jew first; and it is well to remember that all the first apostles and heralds of salvation were from among the Jews, thus fulfilling the prophecy of Isaiah and others, that "the Word of the Lord" should "go forth from Jerusalem"; and hence we see how that, in more than one sense, the first Jewish believers may be said to have ministered to the praise and glory of God. For not only did they, by their faith and repentance, make room for God's glory to be manifested by the extension of mercy and forgiveness to themselves; but they, leading the way, were the occasion of others also embracing the faith, and themselves proclaimed it to the rest of the world.
(A. P. Perceval, B.C. L.)
Parallel VersesKJV: That we should be to the praise of his glory, who first trusted in Christ.