Share 'Spanking. Do you believe in it? Why or why not? And if so, how do you decide when is it time for one?'

I am having a horrible time with my 3.5 y.o. son. I am at my wits end with punishing him, rewarding him for good behavior, time outs, taking favorite toys away. He is still not listening to me. Today, he rode his bike very far away from me to the point where I could not see him. I am considering a spanking at this point but not sure. I would appreciate any suggestions. Thanks.