John 16:33 These things I have spoken unto you, that in me ye might have peace. In the world ye shall have tribulation: but be of good cheer; I have overcome the world.
The Christian life ought to be one of joy, in fact, fullness of joy. That is not to say problem free, trouble free, or trial free but joy in the midst of it all. Jesus said we’d face tribulation (trouble; pressure; that which causes pain or suffering). Salvation doesn’t exempt us from exposure to these things but gives us victory in and over them.
Being of good cheer, being brave, or facing things courageously isn’t because we enjoy trouble or tribulation but because of Jesus’ victory. His victory is our victory that we apply by faith to our lives. Cheer and joy is possible because we believe, for joy is always present when we are believing. Romans 15:13 affirms this connection of believing and joy, “Now the God of hope fill you with all joy and peace in believing, that ye may abound in hope, through the power of the Holy Ghost.”
Jesus HAS overcome the world, not “going to,” not “I will,” not “I’m in the process of,” not “someday I plan to,” but I HAVE overcome the world. He defeated sin, sickness, satan, and the curse in His work on the Cross and His victory is a provision of grace credited to our account because we are in Christ.
He defeated sin in the world.
He defeated sickness, in the world.
He defeated satan, in the world.
He defeated the curse, in the world.
His overcoming the world and victory on the Cross is the basis of our joy, confidence, and courage. There is never a day, present or future, on Earth that can change what He did for us in the past. Our cheer and joy is based on something unchangeable and an already accomplished fact. That’s something to rejoice and shout for joy about.