Since we are in Christ, and Christ is the Reality and the Truth, we are free from the Law of Moses and the Traditions of Men.--So the first things -v16-17- are good things, but they are just pictures of what has fully come. And since it has fully come, we dont need the pictures anymore.--The second things -v18-19- are not good things, they are counterfeits of the real thing. We have the real thing, so we dont need counterfeits.