Elsewhere I have reviewed Dan Barker’s Losing Faith in Faith (see Here). In this critique, I will consider Barker’s response to the Cosmological Argument, which is so abysmally short that I will simply copy the entire thing here:
“‘Everything had a cause, and every cause is the effect of a previous cause. Something must have started it all. God is the first cause, the unmoved mover, the creator and sustainer of the universe.’
The major premise of this argument, ‘everything had a cause,’ is contradicted by the conclusion that ‘God did not have a cause.’ You can’t have it both ways. If everything had to have a cause, then there could not be a first cause. If it is possible to think of a god as uncaused, then it is possible to think the same of the universe.
Some theists, observing that all ‘effects’ need a cause, assert that god is a cause but not an effect. But no one has ever observed an uncaused cause and simply inventing one merely assumes what the argument wishes to prove.” 
This all-too-common objection to the Cosmological Argument is answered easily by the Kalam version, which only states that everything which begins to exist requires a cause. God did not begin to exist, and therefore does not require a cause. Yet, contra Barker, it is not possible to think the same about the universe, for two reasons. First, it is impossible for an actual infinity to be actualized in the real world. Infinity is a mathematical concept that cannot be transferred to the real world without contradiction. Furthermore, even if an actual infinity is possible, it is impossible for the past history to be infinite, since history accumulates by successive addition (i.e., second after second). However, it would be impossible for such successive addition to “add up” to an infinite history, just like it is impossible for someone to actually count to infinity, since it is always possible to count one number higher.
Second, and even more damaging to Barker’s case, scientific evidence has proven unmistakably that the universe began to exist. For example, thermodynamics imply that the universe must be finite in existence, or else the universe would already be in a state of equilibrium or heat death (which contradicts observation.) So the rational man is not justified in thinking of the universe as an uncaused cause.
Thus, the Cosmological Argument need not be question-begging, and it is not possible to construe the universe itself as an uncaused cause. It is quite a shock that this sophomoric attempt to refute the Cosmological Argument is all we get from Barker’s large tome on nonbelief, which is oftentimes considered a practical “end-all” to Christian theism.