The word describes a pact or compact forged when two parties willingly unite their interests. In Scripture it appears once, yet its single placement illuminates the entire doctrine of the believer’s separation unto God.

Biblical setting (2 Corinthians 6:14-18)

Paul walks the Corinthian church through five rhetorical contrasts—partnership, fellowship, harmony, share, and finally synkatathesis—culminating in the question:

“What agreement can exist between the temple of God and idols? For we are the temple of the living God” (2 Corinthians 6:16).

The apostle immediately cites Leviticus 26:12 and Ezekiel 37:27 to assert that the covenant promise of divine indwelling excludes any rival allegiance. Synkatathesis thus serves as the climactic word that bars all syncretism.

Old Testament echoes of exclusive covenant

• Exodus 20:3—no other gods before Yahweh.
• Deuteronomy 7:2—Israel must “make no covenant with them.”
• 1 Kings 18:21—“How long will you waver between two opinions?”

Paul’s choice of vocabulary gathers these strands into one decisive prohibition: covenant loyalty cannot be shared.

Historical‐cultural backdrop

In the Greco-Roman world a συνκατάθεσις sealed business ventures, marriages, political alliances, and cultic rites. By employing a legal term familiar to Corinth’s commercial port, Paul exposes the spiritual treason of blending temple and idol worship. His audience knew that contracts bound participants to all stipulations; entering a rival contract jeopardized both.

Theology of the indwelling temple

1 Corinthians 3:16 and 6:19 declare believers to be God’s sanctuary individually and corporately. Synkatathesis in 2 Corinthians 6 anchors that truth ethically:

1. God’s presence consecrates His people.
2. Consecration demands undivided loyalty.
3. Undivided loyalty forbids any spiritual, moral, or doctrinal compromise with idolatry—whether literal images (1 John 5:21) or any rival trust (Colossians 3:5).

Pastoral and ministry implications

• Personal holiness: followers of Christ must examine every partnership—marriage, business, worship, entertainment—through the lens of covenant purity.
• Corporate purity: churches safeguard doctrine and practice, avoiding alliances that dilute the gospel (Galatians 1:6-9).
• Missional clarity: evangelism invites people not to add Jesus to existing devotions but to forsake idols for the living God (1 Thessalonians 1:9-10).
• Discipleship: teaching on the believer’s identity as God’s temple equips saints to resist cultural pressures toward syncretism.

Summary

Synkatathesis appears but once, yet it seals Paul’s argument that the redeemed community, indwelt by the living God, cannot entertain a joint pact with any form of idolatry. The term crystallizes the biblical call to exclusive covenant fidelity, urging believers to walk in the holiness befitting the temple they now are.