"And they heard the voice of the LORD God walking in the garden in the cool of the day: and Adam and his wife hid themselves from the presence of the LORD God amongst the trees of the garden." (Genesis 3:8)
The presence of the Lord can be either a cause of fear or a source of blessing. Adam and Eve were greatly afraid of His presence because of their sin, and their son Cain "went out from the presence of the LORD" (Genesis 4:16) because of his sin. Yet it will also be to many a time of great joy. "For what is our hope, or joy, or crown of rejoicing? Are not even ye in the presence of our Lord Jesus Christ at his coming?" (1 Thessalonians 2:19).
The difference, of course, is the presence or absence of unforgiven sin in the presence of the Lord. Most of the sixteen occurrences of the phrase stress the judgmental aspect. Those who reject Christ's offer of forgiveness through repentance and faith in His death for our sins will eventually be banned forever from His presence, like Cain. "When the Lord Jesus shall be revealed from heaven with his mighty angels, In flaming fire taking vengeance on them that know not God, and that obey not the gospel of our Lord Jesus Christ: |They| shall be punished with everlasting destruction from the presence of the Lord, and from the glory of his power" (2 Thessalonians 1:7-9).
But for those who have repented of their sins and trusted in Christ for salvation, the prospect of the coming and personal presence of the Lord Jesus is one of joyful anticipation, for "in thy presence is fullness of joy; at thy right hand there are pleasures for evermore" (Psalm 16:11).