God has given the full and final revelation of Himself in the holy history of His Son. Those claiming access to some additional knowledge of God through mystical experience are denying the gospel. In the gospel, believers have equal access to the one knowledge of God. The only way He can be in our hearts is for us to treasure in our hearts His life, death and resurrection. When Christ in the heart is divorced from the Christ of history, the believer becomes preoccupied with his own history instead of God's saving history.
Religious subjectivism can become the most crushing form of legalism.
While we must be careful not to exaggerate, a study of much modern evangelism, piety, and hymnology reveals how serious the influence upon Evangelicalism has been of the combined forces of Pietism, Schleiermacher, and Kant, e.g., in the emphasis upon the centrality of decision, upon the believer and his emotional state, and even upon psychological procedures. Biblical material is used, but with an emphasis and proportion very different from those of the Bible, so that the result is very far from biblical. For a theology cannot be genuinely biblical, however sound its doctrine of Scripture or however strict its use of scriptural material, if it achieves an emphasis which is subjective and therefore anthropological rather than objective and therefore Christological and theological. The believer has no defense against subjective legalism unless the Spirit teaches him that his standing before God, both now and in the final judgment, is based on that concrete historical event completely outside his own experience. This is not the negation of Christian experience but the recognition that it is the byproduct of something more fundamental.