The Greek form este (αΌΟΟΞ) is the second person plural present indicative of the verb eimi (to be). It means simply "you are" β addressing a group. Though grammatically unremarkable, its theological freight in the NT is immense. What believers ARE β collectively and in Christ β is among the most radical declarations of the gospel.
Paul employs este with stunning boldness throughout his epistles. "You are the body of Christ" (1 Cor 12:27). "You are God's building" (1 Cor 3:9). "You are the temple of the Holy Spirit" (1 Cor 6:19). "You are Abraham's offspring" (Gal 3:29). "You are light in the Lord" (Eph 5:8). Each declaration is present tense β not "you will be" or "you should try to be," but este: you are these things now. Identity precedes behavior. The indicative grounds the imperative. You are God's temple β therefore act like it.