The most striking evidence that this life is not the ultimate reality is that we get hungry and thirsty again and again. In an “Ultimate” situation, you need no refills. The word ultimate is the opposite of infinity in a non-finite way: it means you have what you need without needing anymore. So how can a world that constantly changes and “needs” things (soil needs water which needs sunshine for plants to grow which need the right protection from winds and hail and so on) be the ultimate reality? Marx should be ashamed of his “theorems”.