Did you know that what most of America uses in the bath or shower to clean up is not even close to soap? It is a bar made of chemicals and oil refinery by-products. Next time you are at the store check out the box of "soap" that you normally buy to clean up with. You will notice that it doesn't say soap on it anywhere, it will be called a "beauty bar", "cleansing bar" or "moisturizing bar" that is because it legally can not be called soap. It is a bar full of chemicals that you can't pronounce, preservatives and dye.
Cleansing bars are not soap, they are detergents. Detergents are good for washing dishes and clothes because they do an excellent job at removing grease. Therein, however, lies the problem and the reason why they should not be used for cleaning your hands: detergents not only remove the grease from food, oil, etc., they also remove the good oils that are contained in your body. This is why people use lotion after a shower. The lotion replenishes the oils that the detergent stripped away from the skin. One would not need that lotion if one had used real soap.
Real soap is the result of a chemical reaction between fatty acids and one or two bases. To make soap, you need oils and/or fats and lye. The byproduct of this chemical reaction is glycerin. Most of the "soap" you purchase in stores does not contain this naturally-occurring glycerin because the "soap" manufacturers have removed it because the glycerin is worth more than the soap itself. If a commercial "soap" does contain glycerin, it almost always contains glycerin because the "soap" manufacturer added back a little bit for label appeal. This is usually given away by the addition of sodium chloride, salt, on the ingredients list.
Usually, the only pro of a cleansing bar is the price, which is most often rendered mute by the fact that if you take into consideration how long one lasts vs. how long a bar of real soap lasts, the real soap only costs a little more. I also think this is an illogical argument. We take good care of our other organs. We try to eat low sodium food, we take multivitamins, we exercise, we try not to smoke or drink too much, yet then we turn around and abuse our body's largest organ: our skin. If we want to take good care of our heart, brain, and lungs, I think we should logically take just as good care of our body's largest organ by using skin care products that are good for it.