How does Christ promise fellowship to believers?

In Revelation 3:20, Christ states that He stands at the door and knocks, inviting those who hear His voice to open the door for intimate fellowship. This imagery emphasizes the need for an active response from believers; it is not a mere passive acceptance but an engagement with Christ. When one opens the door, it symbolizes belief and trust in Him, leading to a profound relationship characterized by communion and sharing. This fellowship signifies the culmination of salvation and the joy of living in union with Christ, as He promises to come in and sup with those who respond to His invitation.