Are Old Testament saints considered to be part of the Bride of Christ?
No. Even those who lived while Jesus Christ walked the earth cannot be considered part of the Bride of Christ. They were under the Law given to Moses, the Old Covenant. They found favor with God by following the letter of the Law. While not being a part of the Bride, these Old Testament saints will still have a glorious eternity!
The Bride of Christ consists of those believers who lived after the death and resurrection of Jesus. Jesus purchased His Bride with his own blood. The Bride is washed in the blood and stands ready to meet the Bridegroom.