It is a very important Latin phrase that succinctly sums up the essence of the Christian life. R.C. Sproul has a short, accessible, and helpful explanation here, but here’s the heart of it:
“This phrase literally refers to something that takes place in the presence of, or before the face of, God. To live coram Deo is to live one’s entire life in the presence of God, under the authority of God, to the glory of God.”
Coram Deo: the delightful, thrilling, awe-inspiring, beautiful, Biblical vision of the Christian life.
“And whatever you do, in word or deed, do everything in the name of the Lord Jesus, giving thanks to God the Father through Him.” Colossians 3:17