The Diamond Sutra says that all formations are always appearing and disappearing. If you view all appearances as non-appearances, then you can see Buddha.
If you want to see Buddha, Buddha has already disappeared. If you don't want to see Buddha, then seeing, hearing, smelling, touching, tasting - everything is Buddha. The flower is red, the tree is green, the sky is blue. You and these things are never separate. Then you are Buddha.
By Zen Master Seung Sahn