“Van Til often says that the apologist should argue for Christianity ‘as a unit.’ That is, in his view we must not defend a general theism (Ed—“classical theism”) first and later defend Christianity. Rather, the apologist must defend only the distinctive theism of Christianity. As Van Til often put it, we should not try to prove that God exists without considering what kind of God we are proving. And that means, in turn, that we should not try to prove that God exists without defining God in terms of the doctrines of Scripture.
“Does this principle imply that we must prove all the doctrines of Christianity in every apologetic argument we employ? Critics are sometimes tempted to understand Van Til in this way, and Van Til’s own expressions sometimes encouraged that misunderstanding. But Van Til was too thoughtful to teach anything so absurd. Rather, I think what he meant was that (1) the apologist must “presuppose” the full revelation of the Bible in defending the faith. (2) He must not tone down any biblical distinctives in order to make the faith credible. (3) His goal should be to defend (by one argument or the other) the whole of biblical theism, including the authority of Scripture, Trinity, predestination, incarnation, blood atonement, resurrection, and consummation. And (4) the apologist should seek to show that compromise in any of these doctrines leads to incoherence in all human knowledge.
“But beyond these general principles, Van Til also had in mind a focus on divine aseity, the ‘self-contained ontological Trinity.’ For aseity designates what most clearly distinguishes the biblical worldview from its alternatives. Thus, it makes clear in what way Christian teachings are a system of truth, one ‘unit,’ and not just a fortuitous collection of ideas….
“There are traces of the doctrines of aseity in Judaism and Islam, and in heresies such as the view of Jehovah’s Witnesses. On this fact, two remarks (sic): (1) To the extent that they ascribe aseity to God, they do it because they at that point they are influenced by the Bible. (2) Their divergence from Bible teachings leads them to compromise the aseity of God: Islam makes God unknowable and remote, fearing that his direct involvement in the world will revitalize him. If the Islamic God were truly a se, he would not lose his transcendent glory by entering history. Islam also turns predestination into fatalism, thus veering toward (sic) an impersonal concept of God. Judaism today (whatever recent scholarship may conclude about first-century Judaism) is a religion of works, rather than of a an a se God who gives what we cannot repay. And Judaism, like the Jehovah’s Witnesses and other cults, rejects the Trinity, which, as we have seen, is closely related to God’s aseity.” (John Frame, “Divine Aseity and Apologetics,” in Oliphint and Tipton, Revelation and Reason, pages 119-120. The last paragraph is from the footnote on page 120.)