Who is the Bride of Christ and when does the marriage to Christ take place?

The Bride of Christ is the Body of Christ, and the formal marriage to Christ takes place after believers are caught up to be with Him in Heaven. Old Testament Saints are pictured as wedding guests at that Wedding Feast, which is foreshadowed in Psalms 45.

Les teaches that the Bride of Christ is the Body of Christ, and the formal marriage union occurs after the Body has been caught up to be with Him in Heaven. He connects this to the Wedding Feast imagery in Psalms 45:8-12, then notes verse 13's "King's daughter" who is all glorious and present for the Feast. Les also insists the Old Testament Saints are not left out completely; he views them as coming in as the Wedding Guests. This follows his earlier point that after the 75 days run their course, the earth will revert to Eden-like conditions and the curse will be lifted, a prospect beyond human comprehension.

Psalms 45:8

All thy garments smell of myrrh, and aloes, and cassia, out of the ivory palaces, whereby they have made thee glad.

When will the Bride of Christ be united in formal marriage to Christ?

The Bride of Christ, which is the Body of Christ, will be united in formal marriage to Christ after believers have been caught up to be with Him in Heaven. The context describes this as the Wedding Feast, with Old Testament saints present as wedding guests.