Calvinism is a worldview.
A worldview is a network of inter-dependent presuppositions about the most basic and fundamental components of life: reality (metaphysics), knowledge (epistemology) and ethics (axiology). What is real? How can we know truth? What is right?
And Calvinism as a worldview is antithetical to all other approaches to life.
This Antithesis is not primarily external or through the overt actions of Calvinists--many non-Calvinist act and practice the same Ten Commandments. The Antithesis is not primarily expressed in a different art form or science (both which by God's common grace many unbelievers can be successful in).
No. The Antithesis is primarily spiritual or in principal. What Calvinists believe and confess stands them out from the crowd. Especially their view of salvation.
In fact, the Calvinistic worldview is rooted in its view of salvation as expounded in the Bible alone: justification by grace alone through faith alone on account of Christ alone. A salvation consistent in both Testaments. This worldview is more than a question of salvation, yet it is rooted in such truths about salvation.
Why? Because wherever man is the question of his individual standing before the Judge of the universe is forefront. How can I be saved? is the perennial question of the ages. Is salvation through law--mine, God's, the state's--or through faith? If the former, then wherever I am in life I turn that work or thought into an idol to save me. If the latter, then wherever I am in life I turn over to the Lord.
Or to look at it another way: if we have all of God's law (worldview) to cover all our questions but trust in our own self-effort what have we gained? That is why the cornerstone of the Calvinistic Worldview is the Gospel. A Gospel antithetical to all other 'gospels'.
Man is dead in trespasses and sins. Dead. He does not seek God. And he is more than dead, he is the living dead, actively suppressing the truth in unrighteousness. Born speaking lies, he invariably matures in his wickedness until God restrains or transforms his soul (Eph. 1:1-3; Rom. 1:18; Ps. 58:3).
But God in His great love wherein He loves His own, sent Christ to become man, to identify with His people, to obey for His people, to die for His people. For the people He chose to save before the foundations of the world.
It is both the absolute sovereignty and over-ruling dominion of God Almighty and the utter and total depravity of man--in thought, word and deed--that makes Calvinism stand out. And ties its worldview together.
Without a sovereign God who has predestined all things there can be no intelligibility in any endeavor of life--all would be meaningless gibberish--worse, there would be no existence of anything. The Trinity is the precondition--the necessary universal Reality--for creation. Neither logic, science, politics or family life can exist in any coherent manner without the Father, Son and Holy Spirit and their all-encompassing plan for our lives.
And if Christians admit to God's sovereignty in everything but in man's salvation--if they deny that God elects whom He will--then all is lost. If God is not sovereign in your salvation then He is not sovereign anywhere. And if not sovereign anywhere, then all is lost.
The Antithesis is lost. And Humanism has swallowed whole the life of the Christian. In principle. So it should be clear that the great Antithesis is not really between generic Christianity and Darwinism, but Calvinism and Arminianism and any other -ism.
The dangerous worldview of Humanism, Evolutionism and the like is so appealing to American families and churches because they already believe in a key-component. To assert 'free-will' as defined today is to already believe in Humanism. The enemy is not ultimately "out there" against the churches, but "in here" amongst ourselves.
The Antithesis of Calvinism is most clearly portrayed in this perennial question of God's unconditional election of sinners unto salvation and man's bound will. And America--and especially the American churches--will not witness revival or reformation until such truths penetrates their calcifying hearts.