Each letter included one of the descriptions seen in chapter 1. John was in the Spirit. Verse 20 says the candlesticks were symbolic of the seven churches. The gold lampstand was an upright shaft, from each side of which three branches extended. The lampstand provided light for the ministering priests and typified Christ, the Light of the world.
Candlesticks made are like branches shooing out from the lampstand.
And the branches were formed in the shape of almond branches. Jesus is in the midst of the candlesticks. Superimpose a picture of the candlestick over Jesus and you see the idea. We are His extension. John heard a voice and saw candlesticks.