In light of his deterministic outlook, I suppose it doesn't make sense to worry about this, but I cannot see how the concept of regeneration he holds Calvinistically can be consistent with such a view. Regeneration, according to his view, is necessary, foundational and a work of the Holy Spirit. One would think that something established on the basis of the Holy Spirit communicating something into the human soul would be open to other things being communicated as well, building, as it were, upon the foundation of experience the Holy Spirit laid.
But no, apparently something started by the Spirit can be carried on by human effort, at least that is what it appears like to me. Let God stay in the heavens, we have the Scriptures (and they are sufficient)! But those same scriptures describe the Holy Spirit interactively making what is described in them possible for us to experience. It seems to me that is their point; look, for instance, at the following passages: Matthew 13:9-17, 1 Corinthians 2, John 15:26-16:15, Galatians 5:13-25, 1 Corinthians 12:13-31.
The Word truly is our all-sufficient rule for faith and practice. But, whereas the Word is sufficient to describe the kind of things Christians can and should do and believe, the Word can never substitute for the experience of the things it describes. It's not enough to talk about spiritual matters, we need to experience the life of the Spirit. In saying that, I am not suggesting that the Word is not important, I merely am saying that we need to understand its importance rightly.
It is not the hearers of the Word that are blessed, but its doers! That is those who experience what it talks about. The Word is there to tell us what we will and can experience in Christ if we believe. With the scriptures encouragement, may we, with freedom and boldness, endeavor to do so in the Spirit.