The fundamental difference between Calvinists and Arminians is this: Calvinists believe that human beings repent and believe because God causes them to do so by choosing them to be saved. Arminians believe that the ultimate reason people believe is our free will. Perhaps the clearest way to explain the difference is to contrast the five points of Calvinism and Arminianism, commonly known by the acronym TULIP.
Calvinists believe in total depravity. That doesn’t mean people are as evil as they can possibly be, but as sinners they have no ability to choose to be saved (Rom. 8:7-8). Arminians believe people are evil but still have the ability to choose to be saved. Calvinists believe in unconditional election. God from eternity past chooses from his own good pleasure whom will be saved (Eph. 1:4-5; Rom. 9:10-23). Arminians believe God looks ahead and sees who will believe in him and then chooses those whom he foresees will have faith.
Calvinists believe in limited atonement, or what is better described as particular redemption. That means Christ’s death is particularly for the elect and that he has purchased their faith (Rev. 5:9). Arminians believe in unlimited atonement, which means that Christ died for all people, and those who trust in Christ will be saved. Some people are four point Calvinists and reject limited atonement.
Calvinists believe in irresistible grace. This doesn’t mean that no one ever resists God’s grace, but that God overcomes the resistance and hardness of those whom he has chosen (John 6:37, 44, 65; Rom. 8:28-30). Arminians believe that God’s grace is not effectual and can be resisted.
Calvinists believe in perseverance of the saints (John 10:28-30; Rom. 8:28-39; 1 John 2:19). All those whom God has chosen will never fall away from the faith. Arminians teach that believers can lose their salvation.