There are two points to reflect upon on the feast of Jesus Christ, King of the Universe: All mortals should tremble before the Divine, and Jesus is King of the universe.
1- Jesus said to His disciples, on that day, 'The Son of Man comes in His glory' v.31. His angels assembled all people to hear His final word, all trembling before the Lord, because this is the only time all mortals are facing Jesus' glory. The trembling caused by Jesus' glory was so great that it shook all mortals' spirits. Mortals are not made to see the Divine face to face. This echoes what Jesus' apostles experienced up in the mountain, when they saw Jesus transfigured. They heard God's voice like thunder in the sky. They saw Jesus' face and His clothes were shining like morning sunrise, and that made them face down in fear Mt 17,2.
On the judgment day, many will be pleased and filled with great joy, waiting to unite with Jesus. Others will tremble and be saddened. Fearful sadness cripples the spirits of those who choose to follow, not God, but their own will. It will be a bit late to recognize their knowledge has deceived them. They denied the existence of God. Waves of fear invade their hearts, because in a few moments Jesus will decide their fate once and forever because they refused to listen to His voice. The sheep listened to the Shepherd's voice; they know Him and He knows them, John 10. Goats were left outside the gate and wandered aimlessly in the dark. Jesus addresses His sheep. They are blessed by the Father, because they 'had been faithful in small things' Mt 25,21. They lived a life trying to do God's will in serving others. They were faithful to God, becoming agents of God's love and mercy. They now enter God's kingdom, that the Father has made for them since the foundation of the world v. 35. While on earth they lived for the Lord more than for themselves. They tried to make Jesus' words alive for others. To them, Jesus entrusted the mission of caring for the sick, feeding the hungry, visiting the lonely, and dressing the naked. They did their job well. They surrendered their own will to adopt God's will as their own to show God's love, mercy and peace. They are now filled with great joy because the times of tears, mourning, and hunger are declared dead in God's kingdom.
2- We are certain, Jesus is King of the entire universe. We know all forces submitted to Jesus. He had the power to control the force of nature. He quieted the angry sea Mt 14. He calmed the wind by a single command. Sickness and deceases listened to Him. Devils were scared of Him. Mt 8,29. He destroyed forever the power of sin and death. The King of the universe subdued all powers under His feet. The King of the universe demanded His disciples learn from Him, to serve with humble spirit. Mt 11,29. He asked them to do simple and small things for others. It is so simple, that the disciples failed to see the connection that what they did for others, they did for Christ. Jesus identified himself with the poor, the needy and voiceless. He himself had personal experience of these situations when he was on earth. Those who chose to do their own will, not God's, would not be happy to be in the company of those who once were their slaves and servants.