It's true that God often exposes evil and brings His judgment to bear on it in this life. A person who repeatedly abuses their body with drugs or alcohol, for example, will eventually pay a tragic price for their neglect of God's Law. One of the Bible's most solemn warnings is this: "You may be sure that your sin will find you out" (Numbers 32:23).
But your claim that God's judgment is limited only to this life overlooks two important truths. The first is that sometimes evil isn't judged in this life -- at least not as it deserves to be. A corrupt person may cheat and lie all their life, and seemingly get by with it. A tyrannical dictator may oppress his people, only to die peacefully in his sleep. Centuries ago, the prophet Habakkuk cried, "Why do you make me look at injustice?" (Habakkuk 1:3).
But the other truth is that every one of us has done wrong in God's eyes, and we all deserve only His judgment. And some day we each must stand before Him to give an account of our lives. As the Bible says, "For all have sinned and fall short of the glory of God" (Romans 3:23).
This is why we need Jesus Christ, for He alone has provided a way for us to be forgiven and cleansed of our sins. Don't be deceived, but realize your own need for God's forgiveness -- and give your life to Christ today.