Note 1 at Ro 15:22: The cause that Paul was referring to was his desire to preach the Gospel to everyone who had not heard. He had wanted to go to Rome, but he felt it was necessary first to preach the Gospel to everyone in the areas he had already been. This is what he referred to in the next verse when he said, "Now having no more place in these parts" (Ro 15:23). He was saying there was no place left in those parts that hasn't heard the Gospel. Therefore, he was ready to depart for new, un-reached areas.