After outlining the features of the new creation, as the Apostle does in Eph. 5, he comes down to a sort of testing of our hearts in circumstances where we are, and he says, Now let joy abound in your hearts. Let the joy of the Lord be your strength. "Singing and making melody in your heart to the Lord." v. 19. A man may have joy and forget his circumstances, temporarily. But "rejoice evermore, and again I say rejoice." Now that is a test of what you are really. Down here in the wilderness can you give thanks always for all things? It is really a test of grace in its purity in us. The workmanship of God can bear that test. "Rejoice evermore." God is my joy, and I am for Him. Christ is my exceeding great reward. God looks upon Christ. All His own fullness is in Him. Though He remove temporal blessings from us, as He often does, we are to give thanks always for all things. Have I not enough to rejoice in? Not only when He prunes the fig tree and lays bare the vines, but in spiritual conflicts, in temptations that bring out our weakness, "giving thanks always for all things, unto God and the Father, in the name of our Lord Jesus Christ." That is a part of the privilege of the Christian, according to the new nature God has given to us.
G.V. Wigram