Both Jew and Gentile “have sinned, and come short of the glory of God (Rom. 3:23, KJV). Both are rconciled in one body through the cross (cf. Eph. 2:16a). This is the reconciliation that Paul wrote about in 2 Corinthians 5:19, “that is, that God was in Christ reconciling the world to Himself, not imputing their trespasses to them, and has committed to us the word of reconciliation.” The word of reconciliation is the gospel, which, when obeyed, permits the one rendering obedience to it to be reconciled to God first, and then, as Paul pointed out in the previous verses, to other men, and this regardless of their race, sex, or social status (cf. Gal. 3:28). This reconciliation is in the “one body” of Ephesians 1:22-23 and Colossians 1:18, which could not have existed without the work Jesus did for us on the cross, “thereby putting to death the enmity” (Eph 2:16b). How? “By His grace through the redemption that is in Christ, whom God set forth to be a propitiation by His blood, through faith, to demonstrate His righteousness, because in His forbearance God had passed over the sins that were previously committed, to demonstrate at the present time His righteousness, that He might be just and the justifier of the one who has faith in Jesus” (Rom. 3:24-26). Through the cross of Christ sin has been properly dealt with, thus demonstrating that God, even in forgiving our sins, remains, Himself, just. Through the cross of Christ, the penalty for our sins was paid by Jesus on our behalf (cf. Gal. 3:13; 1 Tim 2:6). It is in this way, and this way only, that God remains just while acting as the justifier of all us sinners who exercise faith in His Son. Miss this and you’ll not understand the atonement as God intended for it to be understood.