In Zechariah 6, God brings a vision of 4 chariots with red, white, black, and dappled gray horses who are now acting on God's direction rather than just reporting to God. The presence of chariots suggests battle and implies judgment. Red symbolizes war. Black symbolizes famine. White symbolizes death and the dappled gray likely symbolizes plagues. During the tribulation, there will be wars, famines, plagues, and death as judgment falls for the sins of the nations. God also brings a message of the crowning of Joshua symbolizing our eternal King-Priest - Jesus. God assures us He will cleans the land and protect us. The evil of the nations will be judged but God's children will be delivered. Jesus is returning and will bring perfect peace to earth when He does. It's only through Jesus the altar and the throne are united. He is our perfect High Priest and King of kings for all eternity. We can trust Him with our lives because He is the only sure thing in all the cosmos.