"Blessed are all they that fear the Lord, and walk in His ways" [Psalm 128:1]. He speaks to many; but since these many are one in Christ, in the next words he speaks in the singular: "For you shall eat the labours of your fruits."...When I speak of Christians in the plural, I understand one in the One Christ. You are therefore many, and you are one; we are many, and we are one. How are we many, and yet one? Because we cling unto Him whose members we are; and since our Head is in heaven, that His members may follow....Let us therefore so hear this Psalm, as considering it to be spoken of Christ: and all of us who cling unto the Body of Christ, and have been made members of Christ, walk in the ways of the Lord; and let us fear the Lord with a chaste fear, with a fear that abides for ever....
“Blessed are all who fear the Lord.” The inspired word declared blessed not the one from Abraham’s stock or from Israel’s seed but the person adorned with the fear of God. Blessed Peter also says this in the book of Acts: “In truth I grasp the fact that God shows no partiality, but in every nation the person fearing him and performing righteousness is acceptable to him.” The inspired word also gave a glimpse of the character of the fear of God, adding “those walking in his ways”: 2 “Not everyone saying to me, Lord, Lord, will enter the kingdom of heaven, but the one doing the will of my Father who is in heaven.” So it is typical of those fearing the Lord not to stray from the ways of God but to travel in them without fail.
When he says, “Blessed are all who fear the Lord,” he shows that they are not blessed who fear with troubled mind the dangers of the world when temporal property is lost. For those dangers make people wretched when they torment them with groundless fear. They have no advantage, but rather a dimunition. They do not know an ascent, but rather destruction. In contrast, the fear of the Lord descends from love, is born of charity and is begotten of sweetness. A pious fear comforts the fearful and refreshes the afflicted, and does not know how to lack joy unless such fruit of fear has been put aside. About this fear it is written, “Come, children, listen to me; I will teach you the fear of the Lord.” How advantageous fear is, if children are taught by it! What sort of learning there is which is given with sweet affection!
[AD 430] Augustine of Hippo on Psalms 128:1