Have you ever spoken with someone who could not make up their mind? I heard of a judge who was ruling over a court case. One attorney presented his side, and the judge said, "That's right! That's right!" And the other attorney presented the other side, and the judge said, "That's right! That's right!" The first attorney objected, "Judge, both sides can’t be right!" And the judge said, "That's right! That's right!"
Paul preached before a group of philosophers who were like this judge. They had been discussing ideas and perspectives for so long, and never making up their minds, that they did not give the gospel a warm reception. Not many believed. We are surrounded by spiritual darkness in today's world. The average person excuses their ignorance of spiritual truth by saying they are "open-minded." Some people today say things like, "Oh, I believe in all religions," or "I don't want to take sides." But this simply shows willful ignorance, because philosophies and religions have fundamental differences. By definition they are each exclusive of other views.
Wherever the truth of the gospel is proclaimed, everyone has a moral obligation before God to take sides and to believe. Often it takes some time before the gospel is fully understood, but eventually it will be and then that person, as the Spirit has convicted them, has the opportunity to make a life-changing decision in Christ, and the obligation to do so as well. But if we are faithful, we will see that the Lord will open the door to many hearts.