Well, that is just a saying. It doesn't prove pantheism to be true. I am a Christian who studies Apologetic and I find Buddhism to be unfair and unjust!
Well to practice Buddhism, you have to go all in and be the Buddha. In other words, you ward all suffering and even giving birth is a suffering so if you want to make children, you then can not be the Buddha. No children means the end of everything and the world stops. If everybody dies off then will the next person being reincarnated will come back as a human being? I do not think so.
A buddha temple is very peaceful and very quiet. However, even sitting in one place and meditating can hurts the joints and kinda boring if you sit there for hours upon hours and with that, i say that is a form of suffering.
So basically, if you want to be the Buddha, you have to do nothing because from nothing, you will then find your psycho peace within yourself. If everyone is the buddha then no productivity can be made. Even fasting is a form of suffering. You sit under a tree to meditate and hoping that the fruit from such tree will drop so you can eat it.
It then be the same analogical example when some dumb atheist be telling me that I need to be like my Christ. If everyone is being christ like, nothing can be done also. All we do is walking around and spreading the good news and a job that does not pay. We go from places to places and if people welcome us in then we eat, if not then we go hungry. Same thing can be said with Buddhism monks. They don't beg and only take what is freely given to them.