We know somethings from senses and experience. If we are not to start over from zero at every sum we also learn (know) from authority. That is the mathematical equation 1+1=2, first learned in childhood, remains the same sum into adulthood.
I know, this is not the usual argument for authority. In fact, I believe it does relate directly to authority, because the mathematical surety of the equation is a form of authority. Real authority must have been reliable, be reliable now and promise to remain reliable for the ages to come. However one speaks of 1+1, the summation =2 can be assumed. This is authoritative certainty, demonstrable and sure.
Can religion profess the same demonstrable, sure, certain authority? To be sure, Religious certainty is more difficult to write on a chalkboard, but I hold it is no less certain. In fact, one can borrow from the certainty of other fields to say there must be certainty in religion, for to a world with one physics and one mathematics, unknowable religion simply does not count.
For a moment, consider the Trinity, which appears to be the hot button issue for the Evangelical Atheist writers just now. In the Christian doctrine of the Trinity, God is One God, as in Deuteronomy 6, but God chooses to manifest Godself in Three Persons (Manifestations), which are Father, Son and Holy Spirit. These Three are One but separate and distinct. The writers Hitchens, Dawkins and Rogers all virulently opposed to the Christian faith each point to the doctrine of the Trinity as incomprehensible and indefensible.
Christians welcome this opportunity to explain what we understand of the workings of the Trinity as presented in Scripture, in Church Tradition and in Holy History. The function of the Trinity is, in fact, key to our understanding of God's divine work in salvation.
Consider for the moment that secular mathematicians, themselves not called into the court of public opinion to defend Christian doctrine, routinely accept the ability of individual numbers to hold different properties themselves, in particular in conjunction with other numbers and functions, without ever surrendering their primary unity as a whole. In cooperation with 2, 1 may become 2 or one-half but never loses its actual or implied value (identity).
God, able to do much more than add or subtract, shows powerful divinity (Deity) in expression of Godself as Present in Heaven Perpetually (the Father), Present in Human Form (the Son) and Ever Available (Spirit) without surrendering any part of His divinity, in thought or action. except what He surrenders voluntarily in our behalf.
The Trinity is one of those subjects better understood in its operation (activity, cooperation) than in its designation. If one sincerely wishes to understand the Trinity it is necessary to see the sacrifice of the Christ as beginning in eternity (availability) and then coming into operation in His life and death on earth, culminating in his succession in force by the Holy Spirit.
Simply put, what Jesus sacrifices is the independent exercise of His Godness (Divinity), as Paul has it in Philippians 2:1-11. If we wade this deep into the Trinity, we find the basis for God's ability to be powerful in Heaven, on earth in Jesus and in Heaven and Earth through the Holy Spirit.
Or, think of the Trinity in this way. God sits in Heavenly tribunal, all facets of the Divine Personality in perfect union until the desperate state of man demands action. Remember the functional statement of the Christian Realist, to wit: God comes to us from outside ourselves in Jesus Christ to reveal to us truths about God we could never find if left to ourselves. God reorders the Trinity to include submission, Son To Father and succession, Spirit to Son, in order to address the need of fallen man.
In so doing, God answers forever the questions "Do you not know (care) that we perish?" The Trinitarian Reconstruction of God in eternity effectively changes the outcome of human history in both time and eternity. If God is effective, does this not lead to us to the conclusion that God is authoritative and, finally, that God is knowable? If God is knowable, who would be better to know?
If our Authority for mathematics is the function of past mathematicians and the reliability of their work (whether we fully grasp it all or not), it follows we ought to recognize religious Authority in the same way, that is, dependence on the function of past religious master (Jesus) and the reliability of His continued work (the Spirit), all working to one sum (Father).
Christians who are already settled in their belief in the Trinity could consider this fact; people depend more and more on experts and authorities in this frightening world. Specialized information and applications are sought after and eagerly accepted, if not rigorously followed. Christians might decide to study their (our) knowledge system in order to speak with some meaningful historical authority (reliability). We might be more helpful to God if we know enough to speak a meaningful word to people willing to settle into dialog. "I don't know," is sometimes a helpful answer but it is not the place to start or end, just because we are intellectually lazy.
Opinions expressed here are my own, not those of anyone else, living or dead.