The tender love of God for His servants makes Him concerned for how they feel inside. He wants them to be courageous. Some people think it is okay for a believer to be vexed with doubts and fears, but God does not think so. From this text it is clear that our Master does not want us entangled with fears. He desires for us to live without fretfulness, doubt, and cowardice. Our Master does not think as lightly of our unbelief as we do. When we are despondent, we are subject to a grievous ailment that is not to be trifled with but instead taken at once to the beloved Physician.
Our Lord does not like to see our faces sad. It was a law of Ahasuerus that no one should come into the king's court dressed in mourning: This is not the law of the King of kings, for we may come to Him in mourning. But He still would have us put off the spirit of heaviness and put on the garment of praise, for there are so many reasons to rejoice. The Christian ought to be of a courageous spirit, in order that the Lord may be glorified when trials are bravely endured.
The fearful and fainthearted dishonor their God. Besides, what a bad example it is. This disease of doubtfulness and discouragement is an epidemic that spreads quickly among the Lord's flock. One downcast believer makes twenty souls sad.
Moreover, unless your courage is kept up, Satan will be too much for you. Let your spirit be joyful in God your Savior; the joy of the Lord shall be your strength, and no fiend of hell shall make headway against you. But cowardice lets the banner fall. Moreover, work is easy for the cheerful spirit; and success waits upon cheerfulness. The workers, rejoicing in their God, believing with all their heart, have success guaranteed.
To sow in hope will be to reap in joy; therefore, dear reader, "be strong and very courageous."