Romans 3:23 — For all have sinned, and come short of the glory of God.
Have sinned — done, over with, case closed.
Glory of God = God's moral glory, His perfect character. Also the person of Jesus Christ. For God, who commanded the light to shine out of darkness, hath shined in our hearts, to give the light of the knowledge of the glory of God in the face of Jesus Christ (2 Corinthians 4:6). We do not measure up to the sinlessness of Jesus Christ. In the Old Testament, the standard was the Law. Now it is Jesus Christ.
Come — should be "fall." The word is in the present continuous tense.