Here's a quote from the link I've supplied above. I believe it is very similiar to what the Pastor was saying in his sermon.

Quote
Mental assent to doctrine will not produce regeneration. William Law said:

No one can know the truth of salvation by a mere rational consent to that which is historically said of Christ. Only by an inward experience of His cross, death, and resurrection can the saving power of the gospel be known. For the reality of Christ’s redemption is not in fleshly, finite, outward things - much less in verbal descriptions of them - but is a birth, a life, a spiritual operation.
Most so-called churches of today can be joined by mere mental assent to a set of doctrines. It is readily acknowledged that church rolls are filled with the names of unregenerated people. The Christian life must begin with the subjective experience of the new birth. What a glorious experience when the human spirit is born of the Spirit of God (John 3:6).

Knowledge of the letter does not produce a transformed, mature Christian life. The Apostle Paul’s ministry was not of the letter, but of the Spirit. The result was believers who were “a letter of Christ…written not with ink, but with the Spirit of the living God,…on tablets of human hearts” (2 Cor. 3:3). The conclusion of this same chapter is that the inner experience of the indwelling Spirit will transform the believer into the image of Christ. In his commentary on Colossians 1:27 Dr. John Eadie reveals glorification by the subjective work of Christ.

The glory of Christians is yet to come, but it is certain…. What is partially and progressively enjoyed in time, is fully and forever possessed in heaven…. the basis of this hope of glory is also the subjective work of Christ - by His Spirit within the saint. Not only has he the title to heaven, but he gets maturity for it.
Yet today we see Christians resting in their doctrinal soundness, but with lives void of the fruit of the spirit, void of the divine image, and thinking that because they know the letter of the Word, they know its truth and power.

God’s goal is to produce the Body, the church today, which transformed and transfigured becomes the New Jerusalem eternally. The Body of Christ can only be produced by a succession of subjective experiences. We must first be regenerated (John 3:6). Following the new birth, we are baptized into the Triune God (Matt. 28:19). We are baptized into one Body (1 Cor. 12:13), and become members of the Body of Christ (vv. 12, 14).

Dave.

Knowing that a man is not justified by the works of the law, but by the faith of Jesus Christ, even we have believed in Jesus Christ, that we might be justified by the faith of Christ, and not by the works of the law: for by the works of the law shall no flesh be justified. - Galatians 2:16