St. Theophan the Recluse : 

“However, not everything is accomplished by the Divine Spirit alone. We are expected to do something, and this “something” is of no small importance. The Divine Spirit arouses, the good news indicates where to begin. This is from God. But, having done this, God stops, and awaits our consent. With His first actions, God seems to be asking: “Do you want to get out of trouble? Here, do this.” This moment is the most important. Whoever yields himself to this opens the door to further actions of grace, which bring him then into the realm of the saved. If, however, a person does not yield himself, he cuts off further actions of grace, and he remains among those who perish. St. Paul preached in Areopagus. After the sermon, St., Dionysius and some of the people followed after him, and were baptized. Of the others, one said, “What is this idle talk supposed to be teaching us?” Someone else said, “Come some other time, we will listen to you then,” (see Acts 17:16-34). 

God does not desire the death of a sinner, but He does present a choice, and only he who chooses salvation is saved. If our consent were not required, God could save everyone in a single instant, for he wants everyone to be saved. In that case, no one at all would perish. But out free will does not always act wisely; it becomes stubborn and does not obey Even God. That is how we perish.”