What do you do if an unbeliever has questions or objections to the Gospel you are presenting? Hopefully, you don’t shout louder.
It’s dangerous to assume that the Holy Spirit works only through preaching. He can work through rational argumentation, too. Sometimes, we must appeal to the head and the heart. Jesus said “Love the Lord your God with all your heart, soul, and mind.” If an unbeliever objects that Jesus of Nazareth is simply a fictitious character, the answer is not to tell him to get right with God. The answer is to show him the overwhelming historical evidence confirming the life and death of Jesus—and then tell him to get right with God! Beyond that, It’s unscriptural to refuse to reason with an unbeliever. Look at the ministry of Paul. It was Paul’s standard procedure to present reasons for the truth of the gospel and defend the faith:
And Paul went in, as was his custom, and for three weeks he argued with them from the scriptures, explaining and proving that it was necessary for the Christ to suffer and to rise from the dead. . . . So he argued in the synagogue with the Jews and the devout persons, and in the market place every day with those who chanced to be there. . . . And he entered the synagogue and for three months spoke boldly, arguing and pleading about the kingdom of God. . . . And he expounded the matter to them from morning till evening, testifying to the kingdom of God and trying to convince them about Jesus both from the law of Moses and from the prophets. And some were convinced by what he said, while others disbelieved. (Acts 17:2–3,17; 19:8; 28:23–4 rsv)