The Greek verb antikeimai (ἀντίκειμαι) means to be set against, to oppose, or to be contrary. It is composed of anti (against) and keimai (to lie, be set). It describes active opposition or an adversarial position.
Antikeimai appears in significant New Testament contexts of spiritual warfare and human opposition. In Galatians 5:17, the flesh and Spirit 'are in conflict (antikeitai) with each other, so that you are not to do whatever you want.' This is Paul's most explicit statement of the Christian's internal battle. In 2 Thessalonians 2:4, the 'man of lawlessness' is called 'the opponent (antikeimai).' In 1 Timothy 5:14, Paul speaks of giving 'the enemy (antikeimenos)' no opportunity for slander. The language of opposition runs from flesh vs. Spirit to the cosmic adversary — and Christ's victory encompasses both.