JOEY & CHRISTY SAID:
“How is the human act of evangelism related to God's act of converting a human heart?“
Regeneration creates a predisposition to believe the Gospel, while evangelism supplies the Gospel to be believed.
“God is at liberty to convert someone apart from the evangelist's efforts, right? So does it follow that evangelism isn't intrinsically necessary to conversion?”
i) You seem to be confusing conversion with regeneration. Conversion involves a combination of regeneration and faith. God regenerates the sinner directly. In that causal sense, God regenerates “apart” from evangelism.
ii) However, God doesn’t regenerate a sinner for regeneration’s sake. That’s a means to an end. He regenerates a sinner to bring him to faith. To make him a believer. So regeneration and evangelism are ordinarily coordinated in some fashion. Regeneration supplies the predisposition to exercise saving faith while evangelism supplies the object of saving faith.
“Does the evangelist's method, intelligence, eloquence, or persuasiveness play a role in whether his audience is converted? But still, it seems most evangelists try to improve their method, education, etc. Why?”
That can be a factor in conversion, but an insufficient condition.
“What is my duty as an evangelist? To only proclaim the Gospel of Jesus? Or should I also try to persuade people to believe the Gospel of Jesus, to defend the Gospel of Jesus, to answer objections?”
You should do the best you can, given your time, abilities, and opportunities.
“Can I, as an evangelist, ‘mess things up’ so that someone whom God might have saved had I presented the Gospel in a more compelling, charismatic, scholarly, or clear way, not find salvation?”
In a counterfactual sense. But God coordinates the message, messenger, and audience to achieve his goal.
“I've heard Calvinist evangelists say things like, ‘Of course you don't understand. You're a pagan unbeliever?’ This seems rude, but would such statements be considered rude by mainstream Calvinists? Would mainstream Calvinists rebuke an evangelist who said this kind of thing?”
Some of the unregenerate will never understand because they are reprobates. Some of the unregenerate will come to an understanding after God regenerates them.
“When someone doesn't believe the Gospel after it has been clearly presented, whose fault is it? The evangelist's fault for not doing a better job or the unbeliever's fault for having a hard, unrepentant heart, or God's fault for not electing him?”
It’s ultimately the fault of the unbeliever.
“I don't know or care who Fred Phelps is. Here's my question: you said that the hyper-Calvinist position believes that you don't have to try to convince people of their truth or try to convert people because converting people is God's job. Our job is to faithfully preach the Gospel. If this is the hyper-Calvinist position, what is the standard Calvinist's position?”
i) There’s nothing special that a Reformed pastor needs to do. He has the same message for everyone in the audience. Elect or reprobate. Regenerate or unregenerate. Devout believer, nominal believer, or closet apostate.
ii) He can preach through books of the Bible. Or do topical sermons on Christian doctrine and ethics. He can teach people who Jesus is, what he did, is doing, shall do, and why. He can teach people that whoever repents of his sin and trusts in Jesus to save him will be forgiven. Since the “offer” of the gospel is a conditional offer, it can be offered to every listener. Whoever accepts the terms of the offer will receive what is offered.
iii) We also have examples of inspired evangelistic preaching in the Gospels and the Book of Acts. Those can be used as models for how to preach the gospel.
iv) Preaching needn't be specifically evangelistic to be instrumental in conversion. Expository preaching through various books of the Bible can also have that effect. There’s a place for evangelistic preaching, but that’s a matter of emphasis.