I've met a lot of people who bore what I call "willful ignorance." That is, they've received correction, and don't want to reform. They've been told what is light and what is darkness, and they still refuse to come to the light. They have the truth right in front of them, and they still refuse to believe it. I know full well that no argument alone can win a soul. I know that. I realize that a person's regeneration comes only by the will of God (Jn 1:12-13) - again, I know all that.
All the same, it gets hard when that realization hits a bit close to home. When family or friends are the ones displaying it. It gets even harder when you have immense respect and love for the individual, and you just want to shake them and say to them "Wake up!" You want to ask why they can be so intelligent and well rounded in certain areas, and yet such a dunderhead with this topic.
I recall once a story by Christian apologist James White, who, after a debate, got into a discussion with a passionate Roman Catholic over sola scriptura and related subjects. After blowing every argument he made out of the water, the guy threw his hands up and said, "Well look, you're the apologist, not me." Then sometime later, James White was headed out, and saw the man talking with someone else on the same subject. As he was passing by, James White overheard him making the exact same arguments he had made before. It's easy for us to hear a story like that and say, "Wow, that's really sad for that individual." It's hard, however, when we know that such a person is someone we consider a friend, or know as a family member. It's not easy to dismiss or disregard. It gets painful, and hurtful really.
It's a reminder, one might suppose, that we should treat all men like friends and family when it comes to the Gospel. It's a reminder that we should remember even those who are stubborn against the truth with whom we have no relation should be treated with respect, and should be given the truth of God no less than those we know personally. Whether its a random individual online, an in person encounter, a friend, or a family member, all who are without the truth need He who is Truth. God bless.