If you carefully examine Jesus' life and teachings, I believe you'll conclude that He was neither an optimist nor a pessimist. Instead, He was a realist -- that is, He was pessimistic about some things and optimistic about others.
Let me explain. On one hand, Jesus was a pessimist about our ability to solve life's deepest problems apart from God. The reason is that our deepest problems ultimately come from within us, and are spiritual in nature. Why are we unable to put an end to war, or greed, or hatred, or lust? These problems, Jesus said, come from within our hearts -- and only God can solve them in a lasting way.
On the other hand, Jesus was an optimist about the future -- because He knew that the future is in God's hands. Someday He will intervene, and all the evils and injustices of this world will be over. The Bible says, "Behold, I will create new heavens and a new earth. The former things will not be remembered" (Isaiah 65:17).
But Jesus was an optimist for another reason: He knew that when we commit ourselves to Him and make Him the foundation of our lives, our sins will be forgiven and our lives will be changed.
Has this happened to you? It can, as you realize your need for God's help and put your life and your future into Christ's hands. God's promise is for you: "I will give you a new heart and put a new spirit in you; I will remove from you your heart of stone" (Ezekiel 36:26).