II. And now, secondly, the 'joy of the Lord' or rejoicing in God, is a matter of Christian duty.
It is a commandment here, and it is a command in the New Testament as well. 'Neither be ye sorry, for the joy of the Lord is your strength.' I need not quote to you the frequent repetitions of the same injunction which the Apostle Paul gives us, 'Rejoice in the Lord always, and again I say, Rejoice'; 'Rejoice evermore,' and the like. The fact that this joy is enjoined us suggests to us a thought or two, worth looking at.
You may say with truth, 'My emotions of joy and sorrow are not under my own control: I cannot help being glad and sad as circumstances dictate.' But yet here it lies, a commandment. It is a duty, a thing that the Apostle enjoins; in which, of course, is implied, that somehow or other it is to a large extent within one's own power, and that even the indulgence in this emotion, and the degree to which a Christian life shall be a cheerful life, is dependent in a large measure on our own volitions, and stands on the same footing as our obedience to God's other commandments.
We _can_ to a very great extent control even our own emotions; but then, besides, we can do more than that. It may be quite true, that you cannot help feeling sorrowful in the presence of sorrowful thoughts, and glad in the presence of thoughts that naturally kindle gladness. But I will tell you what you can do or refrain from doing--you can either go and stand in the light, or you can go and stand in the shadow. You can either fix your attention upon, and make the predominant subject of your religious contemplations, a truth which shall make you glad and strong, or a half-truth, which shall make you sorrowful, and therefore weak. Your meditations may either centre mainly upon your own selves, your faults and failings, and the like; or they may centre mainly upon God and His love, Christ and His grace, the Holy Spirit and His communion. You may either fill your soul with joyful thoughts, or though a true Christian, a real, devout, God-accepted believer, you may be so misapprehending the nature of the Gospel, and your relation to it, its promises and precepts, its duties and predictions, as that the prevalent tinge and cast of your religion shall be solemn and almost gloomy, and not lighted up and irradiated with the felt sense of God's presence--with the strong, healthy consciousness that you are a forgiven and justified man, and that you are going to be a glorified one.
And thus far (and it is a long way) by the selection or the rejection of the appropriate and proper subjects which shall make the main portion of our religious contemplation, and shall be the food of our devout thoughts, we can determine the complexion of our religious life. Just as you inject colouring matter into the fibres of some anatomical preparation; so a Christian may, as it were, inject into all the veins of his religious character and life, either the bright tints of gladness or the dark ones of self-despondency; and the result will be according to the thing that he has put into them. If your thoughts are chiefly occupied with God, and what He has done and is for you, then you will have peaceful joy. If, on the other hand, they are bent ever on yourself and your own unbelief, then you will always be sad. You can make your choice.
Christian men, the joy of the Lord is a duty. It is so because, as we have seen, it is the natural effect of faith, because we can do much to regulate our emotions directly, and much more to determine them by determining what set of thoughts shall engage us. A wise and strong faith is our duty. To keep our emotional nature well under control of reason and will is our duty. To lose thoughts of ourselves in God's truth about Himself is our duty. If we do these things, we cannot fail to have Christ's joy remaining in us, and making ours full. If we have not that blessed possession abiding with us, which He lived and died to give us, there is something wrong in us somewhere.