An excellent question!
It would require quite a bit to lay out all the differences. The short answer is that Presbyterianism's foundation rests upon the five solas of the Reformation:
Sola Scriptura - Scripture Alone
Solus Christus - Christ Alone
Sola Gratia - Grace Alone
Sola Fide - Faith Alone
Soli Deo Gloria - The Glory of God Alone
Presbyterianism places a very high view on the sovereignty of God and the doctrines of grace:
T = The Problem (
Total Depravity) – Grace Needed
U = The Remedy (
Unconditional Election) – Grace Conceived
L = The Means (
Limited Atonement) – Grace Merited
I = The Application (
Irresistible Grace) – Grace Applied
P = The Result (
Perseverance of the Saints) – Grace Preserved
These specific doctrines have been popularly called Calvinism, after John Calvin. A summary follows:
TOTAL DEPRAVITY (Total Inability) - The Calvinist believes, as did Martin Luther, that man has a will and his will is in bondage to his nature.
The will of man is free to choose according to the dictates of his nature, but it is not free to contradict his nature. From Adam's fall the nature of every man has been sinful. Therefore, every action of the unsaved man is sinful and rebellious; it is stained through and through by his sin nature. The unregenerate man cannot perform even one single righteous or pleasing work with respect to a holy God.
UNCONDITIONAL ELECTION - The Calvinist believes that God’s election is truly unconditional. The foreknowledge of God is based upon His decree, plan, and purpose; it is the expression of His will and good pleasure, not a response to man's free-will choices.
Election is the sovereign act of God the Father choosing specific individuals out from the entire body of condemned and fallen humanity. These individuals were chosen before the foundations of the universe and not as a result of any foreseen merit or activity or decision on their part. These chosen or elect individuals are purposed to become monuments to the Father's love for all of eternity. In this regard the Calvinist understands election as an example of God’s "
love before time."
LIMITED ATONEMENT - The Calvinist believes that in order to accomplish the specific will of the Father, Christ took to the Cross the sins of the elect. Christ died for the sins of men without distinction as to race or nationality (that is, Jew or Gentile).
Christ provided a complete and effectual atonement for their sins. Those whom Christ redeemed, Christ
really and truly redeemed (
actual not
potential). Though infinite in value, Christ's atoning work was specific in its design. Some Calvinists prefer to call this "definite atonement" or "particular redemption". The death of Christ at Calvary does not make men savable, but rather it saves men completely. The Cross is a completed, successful work that requires no assistance from man. The Calvinist believes that Christ died for all of the sins of the elect.
IRRESISTIBLE GRACE - The Calvinist believes that the Holy Spirit, in agreement with the electing will of the Father and the atoning work of the Son, does in the fullness of time
quicken the dead spirit of a man and give to him the gift of saving faith in the Lord Jesus Christ. For the Calvinist, the logical order of salvation is regeneration first, followed by faith/believing. Since dead men do not respond, God must make them alive first (Eph 2:4-5); regeneration, of necessity, precedes any action or activity on the part of man, including faith and repentance. Hence, every single individual upon whom the Spirit of God moves savingly is regenerated, born again, adopted, grafted in, and saved eternally.
PERSEVERANCE OF THE SAINTS - The Calvinist believes that since God is the Author and Finisher of our faith, man cannot fall away from eternal salvation. Once a man has been born-again he cannot be unborn-again. Furthermore, the elect of God will definitely manifest evidences of their salvation by means of good works. The elect shall, by the grace of God and without exception, ultimately persevere in righteousness. The eternal security of the believer in the Lord Jesus Christ is demonstrated by the persevering faith and righteousness wrought by the grace of God in His little begotten ones.
Presbyterianism is much more than this, for it is a system of beliefs that also encompasses church polity and Christian social action defined best in the Westminster Standards (see list below), that all Presbyterian churches assent to as best representing the Scripture's teachings:
Westminster Confession of Faith (WCF):
Westminster Confession of Faith
Westminster Larger Confession (WLC):
Westminster Larger Catechism
Westminster Shorter Confession (WSC):
Westminster Shorter Catechism
The sticky post in this forum also contains some useful resources you may want to review:
http://www.christianforums.com/t7398432/
For starters, review the WCF and you will be well on your way towards understanding the Presbyterian walk of faith. Feel free to ask questions!
You may also want to visit one of the conservative Presbyterian churches in your area, such as a
PCA church (my denomination).
AMR