Joy.

 
What Nehemiah said to the people contains a very fine truth “the joy of the Lord is your strength.” see chapter 8:10. Joy is strength, we may prove it every hour. And we may know it from the working of the opposite thing so often also experienced, that sadness is weakness. An observer of men once said, “A merry heart goes all the day, a sad one tires in a mile,” and his words adopted this divine thought, this thought of the Spirit, “joy is strength.” But it may be more. If it be great, it will be strength in proportion, but if it he perfect, it will be nothing less than victory. It will then be more than armor for a fight. It will lead on to conquest without any fight at all. It will do all the business for multitudes, prowess, and tactics together, by a single energy. At times it does more than give the soul an advantage and a strength in fighting with corruptions, it ensures it victory. We have an interesting exhibition of the power of joy in 1 Chronicles 12:38, 4038All these men of war, that could keep rank, came with a perfect heart to Hebron, to make David king over all Israel: and all the rest also of Israel were of one heart to make David king. (1 Chronicles 12:38)
40Moreover they that were nigh them, even unto Issachar and Zebulun and Naphtali, brought bread on asses, and on camels, and on mules, and on oxen, and meat, meal, cakes of figs, and bunches of raisins, and wine, and oil, and oxen, and sheep abundantly: for there was joy in Israel. (1 Chronicles 12:40). On that bright and animated occasion, Judah could not have provoked Ephraim, nor could Ephraim have envied Judah. A stranger had entered the scene who had authority to command these away from themselves, and to conform them both to himself. Joy and a common object alone were felt and acknowledged. David was to be made king, that was the common joy that had just entered; and one heart was generated by one object. Through the joy that accompanied that object, there was joy in Israel, (verse 40) that accounts for all this scene of allayed jealousies and private feelings, and for the presence and exercise of loving affections. None in Israel had then what are called “separate interests.” Joy, perfect and common as it was, made that an impossibility. This was one of the days of heaven upon earth, (Deut. 11:2121That your days may be multiplied, and the days of your children, in the land which the Lord sware unto your fathers to give them, as the days of heaven upon the earth. (Deuteronomy 11:21)) for in heaven, and that forever, joy will be triumphant, admitting of nothing inconsistent with itself.