Just like the Passover was a pre-representation of the Christ to come so was the Menorah. The center candle lights the other candles representing Christ being the light of the world. To replace the Menorah would be the same as getting rid of communion or The Lord's Supper, which stems from Passover. There was a reason that God commanded these things be celebrated and done in the Old Testament, as a foreshadowing of what was to come. Just like "future proves past".

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