You may think that if there is no purpose or no goal in our practice, we will not know what to do. But there is a way. The way to practice without having any goal is to limit your activity, or to be concentrated on what you are doing in this moment. Instead of having some particular object in mind, you should limit your activity. When your mind is wandering about elsewhere you have no chance to express yourself. But if you limit your activity to what you can do just now, in this moment, then you can express fully your true nature, which is the universal Buddha nature. This is our way.
When we practice zazen we limit our activity to the smallest extent. Just keeping the right posture and being concentrated on sitting is how we express the universal nature. Then we become Buddha, and we express Buddha nature. So instead of having some object of worship, we just concentrate on the activity which we do in each moment. When you bow, you should just bow; when you sit, you should just sit; when you eat, you should just eat. If you do this, the universal nature is there.
~Shunryu Suzuki, in Zen Mind, Beginner's Mind