The Second Coming of Christ symbolizes a collective realization. It means that when everyone on the planet is Self-Realized, the Christ (that dwells in all beings and effect) in all its individual and collective expressions, will walk the earth bringing with it a state of consciousness known as heaven, whereby the lion (spirit) will lay down with the lamb (soul) and peace on earth (Son) will reign.
Remember the bible was meant to be discerned and interpreted allegorically and metaphysically. It was never meant to be taken literally or used as a history book. The bible is the story of one man's journey back home to himself in and of Spirit.
For a metaphysical interpretation of the bible, I highly recommend the site 'The Spirit of Scripture" at: https://www.spiritofthescripture.com/