Answer
Decisional regeneration, sometimes referred to as decision theology, is the belief that a person must make a decision for Christ, consciously accepting Him as Savior, in order to be saved. According to decision theology, the new birth occurs when someone 1) hears the gospel, 2) is convicted of the truth of the gospel, 3) understands the need for salvation, and 4) chooses to accept Christ rather than reject Him. Often, the decision to accept Christ is marked by an action such as walking an aisle, praying a "sinner’s prayer," signing a decision card, or similar activity.
Detractors of decision theology consider it a misleading and dangerous teaching because it gives man too much control over his salvation. Some see decisional regeneration (salvation depends on making a decision) akin to baptismal regeneration (salvation depends on being baptized) and other works-based systems. If salvation is by grace, then it is an internal work of the Holy Spirit, occurring at the time of His choosing. Decisional regeneration, on the other hand, posits that the moment of salvation occurs when someone makes a choice to “accept Christ.” This, say opponents, is tantamount to salvation by works, because exercising the will is a human work and therefore cannot be part of salvation.
Some are opposed to decision theology because it risks associating a spiritual event with a physical action. Telling someone to "make a decision for Christ" and to "express" that decision outwardly fosters the notion that salvation is synonymous with walking an aisle or reciting a prayer instead of being the work of the Holy Spirit (John 3:8). This false association, in turn, can lead to false conversions, because someone who walks an aisle after a sermon may think he is saved (on the basis of an emotional experience), when there has been no work of God in his heart. Also, the detractors of decision theology are quick to point out that nowhere in the Bible are "decisions for Christ" mentioned, nor is anyone commanded to "accept Christ" or to "ask Him into your heart."
Further, Scripture says that man in his natural state is incapable of choosing Christ. He is "dead" in sin (Ephesians 2:1), he cannot please God (Romans 8:8), and he is utterly helpless to come to God on his own (John 6:44-45). There is "no one who seeks God" (Romans 3:11); an unsaved person is unable to "accept the things that come from the Spirit of God" (1 Corinthians 2:14). This being the case, asking a non-Christian to make a decision for Christ is like asking a corpse to dance. Divine intervention is necessary.
Central to the debate over decision theology is the debate over monergism vs. synergism. Is salvation God’s work or man’s—or both? Monergism, closely allied with Calvinism and its tenet of irresistible grace, teaches that God is solely responsible for all aspects of our salvation. God sovereignly saves without any cooperation from us whatsoever, even giving us the faith to believe (Ephesians 2:8-9). Synergism teaches that we cooperate in our salvation to some degree. Decisional regeneration can be seen as synergistic in that we must decide to accept Christ—a very limited cooperation, but cooperation nonetheless.
The Bible is clear that salvation is totally the work of God. We can do nothing to secure salvation for ourselves (Romans 3:20). The Lord chooses us (John 15:16), draws us to Himself (John 6:44), gives us life (John 14:6), and preserves us (John 10:28). The new birth is not the result "of human decision" (John 1:13). Just as the Lord brought life to the valley of dry bones (Ezekiel 37), Jesus "gives life to whom he is pleased to give it" (John 5:21). At the same time, the Bible commands everyone to repent (Acts 3:19, 17:30) and to believe in Christ (Acts 16:31). While the words "make a decision for Christ" are not used in Scripture, the fact that we are commanded to repent seems to imply an exercise of the will.
How is one saved? By grace through faith—and even faith is a gift created through the hearing of God’s Word (Romans 10:17). Salvation does not come by walking an aisle or raising a hand. Saying a prayer does not save anyone. Reading and agreeing with the salvation pages on GotQuestions.org cannot save. Salvation is making a new spiritual creation, something only the Holy Spirit can accomplish.
Does this mean that it is wrong for an evangelist to hold an ”altar call” after his message? Not at all. However, we must be careful never to attribute our spiritual peace with God to a physical act of our own. Coming to the front of a church is not the same thing as coming to Christ. Also, we should remember that simply "making a decision" of some kind is not what saves us; it is the all-powerful, sovereign work of God in Christ that saves. Rather than calling on people to "invite Jesus to come in," it would perhaps be better to urge them to repent of their sin and cast themselves on the mercy of God in Christ.