Agreement or harmony between persons or things. Paul asks rhetorically in 2 Corinthians 6:15, 'What harmony has Christ with Belial?'—what agreement exists between the Messiah and Satan? The expected answer is 'none,' establishing that believers cannot maintain fellowship with unbelievers in religious practices. The word denotes not just absence of conflict but positive accord, shared purpose, alignment of will. Paul's string of rhetorical questions (partnership, fellowship, harmony, agreement) pile up images of unity to show the impossibility of yoking righteousness with lawlessness.