LORD, what is man, that You take knowledge of him? Or the son of man, that You are mindful of him?
Man is like a breath; His days are like a passing shadow.

Rescue me and deliver me from the hand of foreigners, Whose mouth speaks lying words, And whose right hand is a right hand of falsehood—
That our sons may be as plants grown up in their youth; That our daughters may be as pillars, Sculptured in palace style;
That our barns may be full, supplying all kinds of produce; That our sheep may bring forth thousands And ten thousands in our fields;
That our oxen may be well laden; That there be no breaking in or going out; That there be no outcry in our streets.
Happy are the people who are in such a state; Happy are the people whose God is the LORD!

We see here that David’s praise of God as his all-sufficient help is enhanced by a recognition of the intrinsic worthlessness of humans. Here we have David confidently imploring God’s intervention against his enemies, and he breaks forth into praise and joyful anticipations of the prosperity of his kingdom, when freed from proud, arrogant, ingorant and wicked men (Jamieson et al.)

For a Christian this is a divine example of a believer relying upon the hand of the LORD to fight his enemies - not physically but those that intrude spiritually. Those foreign to the precepts of the LORD (not merely people of different cultures), including those directly opposed to Him, spreading deceit and lies, influencing unrighteousness, denying His creation work and therefore ownership of this planet and all that is in it. Our happiness comes from being a believer in Jesus Christ, and thus a child of God.

Jamieson, Fausset and Brown Commentary