"How can he think we have a future together with so much deception going on?"
He is an addict, he is just doing what addicts do, he "thinks" that you will stay with him
as his lies are still working with you. Addicts lie, then they lie somemore, they ALL do it, and many continue to lie well after they are sober. It just becomes another habit.
Take some time to read cynical one's blogs which can be gotten to at the top of this page. There are blogs there than will be very helpful to you to better understand addiction. This disease is baffling and cunning and will adversely affect all it comes in contact with.
It is all about his actions, not his words...they mean nothing. He will say anything to hide his addiction, which as it stands today, is his first love.
Knowledge is power, learn all you can.