I think it's the "mind" why ? because if you're sick and you instill in your mind that you're not, then you will really feel better . you can eat junk foods and do all the vices that you want but not gaining any implications because that's the medical term for "Placebo effect" wherein you can be well and good by just thinking that you are really in good condition. And through being mindful you will be able to think anything and make techniques upon gaining money. That's the power of the strongest element which I think is the mind.