The wedding feast of the Lamb will be when God's people celebrate their union with him, in both being presented to him and celebrating with him. People actually become united to him, when they place their faith in him. But in a sense the bride as a whole will be united to Christ on that wonderful day. Anyone and everyone is invited to become part of the bride, the church, by repenting and placing their faith in Christ.
Watch: https://youtu.be/Oubk2Qc3_K8