This is the happiness for which we are hardwired, and which should guide all of our thoughts and actions in this life. This innate desire for happiness was placed within our hearts in order to draw us to God, who is the source of all good and who alone completely satisfies us. Happiness, then, means not merely subjective contentment, but also real blessedness, the state of possessing what is objectively good for us. It is contentment, but contentment in the true good.
To rejoice as we ought means recommitting ourselves to Jesus, making His ways our ways; His thoughts our thoughts. The one who calls you is faithful, and he will also accomplish it. All we need do is respond to the promptings of the Holy Spirit to be Jesus-centered, and come what may, we will, deep within, rejoice in the purest sense and thus be ready for the coming of our Lord Jesus Christ.
David J. Conrad