Is tax evasion even possible?

Taxes are taken out first from your paycheck. Then when you buy something you are taxed by state, county, and federal sales taxes. Why the three different taxes shouldn't their just be one? Why should an employee even be taxed when the empoloyer is supposed to pay and the products are taxed ahead of time so companies should not have to pay either. Then there is property taxes do we really just rent from the government why even buy land at all there is a sales tax on that and then a yearly tax. Is that right? Then personal property tax you bought the stuff once and paid taxes on it when you bought it right so why would you have to pay it yearly? So when is it possiple to evade taxes? Is the Government really just profiting on the people and are we really just slaves to the government? So is tax evasion really possible? What are your thoughts on this?