As do many other psalms, Psalm 138 speaks of God's "kindness" and "truth". There is a great variety of translations for these two terms, especially for the first one. This variety of translations merely points to the profundity of the term and the wide range of meaning which they cover. In spite of the difficulty of finding a fitting translation, the meaning is clear.

"Kindness" indicates the fulness of God's love for us as it has been expressed throughout the ages in different covenants. This kindness is God's "covenantal love". Whenever we speak of "love", we are too inclined to think of an emotion, but love is much deeper than emotions even if it is frequently expressed in emotional ways. The addition of "truth" to "kindness" reveals something of the meaning of this "covenantal love". While we read "truth" and "love" as two different terms, they are in fact mutually explanatory. For this "truth" of God implies "fidelity". God has always been faithful to His promises - the next verse actually speaks of God's promise. As Christians, we see God's covenantal love and fidelity especially in the gift of His Son, and in the new and eternal covenant which Jesus established in His Paschal mystery.