THE BIBLE ALONE IS DIVINELY INSPIRED: HUMAN ORIGIN IS TOO IMPLAUSIBLE
SUPERFICIAL
DOUBTS
Skeptic #1:
– INCLUSIVITY –
The Bible claims divine inspiration (“All Scripture is given by inspiration of God ....” – 2 Tim. 3:16). But that does not say other “holy books,” some of which also claim divine inspiration, are not equally divinely inspired.
Skeptic #2:
– RELATIVITY –
The Bible states God's Word is “forever settled in heaven” (Psalm 119:89). But this does not mean it is forever settled on Earth, or that it is even knowable for sure now on Earth. Different “holy books” clash on what God's Word is.
Skeptic #3:
– TENTATIVITY –
The Book of Revelation curses adding to or detracting from it (Rev. 22:18-19). But strictly construed, this arguably implies that man may freely revise anything or everything in the other 65 books of Scripture risk-free whenever it suits.		  
 ONLY THE BIBLE INSULTS HUMAN NATURE.
If of human origin,
why insult human nature?
FUNDAMENTAL PROOFS
 Other “holy books” are optimistic on human nature because they teach uplift by works, i.e., that man is either born good, or can self-reform, thus earning final bliss. The Bible is uniquely pessimistic on human nature (Psalm 51:5; Romans 3:10-23). Man's depravity implies Christ's deity, and vice versa. If evil man cannot self-regenerate, he needs a divine Savior. If Christ had to be divine to atone for sin, corrupt man cannot auto-evolve into goodness. Christ's deity voids all do-it-yourself plans of perfecting by works. Madison's Journal of the 1787 U.S. Constitutional Convention, and The Federalist Papers, both reek with pessimism on human nature. Checks and balances, separation of powers, and federalism incorporate that Christocentric premise into this definition of political liberty.
Skeptic #4: The Bible is not uniquely pessimistic on human nature.
Secular writers Nicolo Machiavelli (The Prince, 1532) and Thomas Hobbes (Leviathan, 1651) were likewise negative.		 
ONLY THE BIBLE DILUTES HUMAN POWER. 
Machiavelli and Hobbes were Biblically pessimistic on human nature. Yet they were anti-Biblical – non-Trinitarian – on sovereignty. As humanists, both lodged sovereignty with rulers: Machiavelli, out of rulers' self-interest; Hobbes, to impose and keep order. Biblical Trinitarianism shares sovereignty at the divine level: Centralization = decentralization because all three Persons of the Godhead are equally fully divine. Biblical Trinitarianism divides sovereignty at the human level: Self-, family-, church-, and civil-government divide sovereignty. The Constitution's silence on whether or not a state may secede, shows its Trinitarian principle of shared sovereignty, applied as divided sovereignty. Had it forbidden secession, the federal government would be ultimately sovereign. Had it allowed it, each state would be.
If of human origin,
why dilute human power?
  Humanistic sovereignty is indivisible: The many submit to the one (dictatorship), or the group submits to individuals (anarchy). Divided sovereignty – “decentralized centralization” – with several semi-sovereign autonomous nodes, is logically impossible. Trinitarian divided sovereignty among men fits perfectly with pessimism on human nature. It allocates power among non-competing, complementary spheres of human government under Biblical principles, none subordinate to the others, to restrain wicked impulses. Divinely-revealed Trinitarian Christocentrism alone unlocks heretofore-unknown “deep things of God” (1 Corinthians 2:9-10), and previously-inaccessible “wisdom and knowledge,” otherwise hidden in Christ (Colossians 2:2-3), all totally anathema to human selfishness.