I. David begins by saying, "I will bless the Lord at all times." This should be our resolution also. (1) There is a great power in praising. It leads one away from self-consciousness. (2) Praise is a very strengthening thing. Our Lord strengthened Himself for the last conflict by praise. The spirit of praise is the very essence of heaven, and the man who lives in praise will live in "heavenly places in Christ Jesus." (3) Praise is a very reasonable thing. There is always something to praise God for. Let us learn the lesson, "We will praise the Lord at all times,in the hour of adversity as well as in the day of joy;" and depend upon it, the more you are praising, the more you will have to praise for.
II. The second point is confession. David goes on to say, "My soul shall make her boast in the Lord, and the humble shall hear thereof and be glad." So far from there being anything presumptuous in this confession of our faith in the Lord Jesus, "the humble shall hear thereof and be glad." If you determine to hide your feelings in your heart, you will soon have nothing to hide.
III. The third point is fellowship: "O magnify the Lord with me," etc. When God made man, He made him first of all alone, and then He decided it was not good for him to be alone; and ever since then God has so arranged it that man is never left altogether alone, or only under very exceptional circumstances. We are born into the world of our fellow-men; when we are born again, we are introduced into a new society, with a fellowship far more real than is to be found in the society of the world.
IV. The Christian life must be (1) a life of security; (2) a life of faith; (3) a life of labour.
W. Hay Aitken, Mission Sermons,1st series, p. 310.