I'm afraid I've committed the unpardonable sin. How can I know if my repentance is genuine, or if it is just my wicked heart falsely assuring me that I am in a right standing with God?
Those feel like two questions to me. Let's see if I can answer them separately and then try to figure out the connection.
"I'm afraid that I've committed the unpardonable sin" is one thing. To worry that our repentance is not genuine and that our hearts are falsely assuring us, that's a problem for lots of people without any reference to the unpardonable sin at all.
In other words, any of us would ask at any given time, "Am I real? Am I playing games? Did I just inherit this from my parents? Is my faith real?" And the answer to that question will probably wind up answering the first one.
When the question arises, "Is my faith authentic?"—which it should, because the Bible says, "Test yourselves to see if you are in the faith"—the answer is almost never found with the kind of soul-satisfying certainty that you want by looking in and peeling the onion of your heart.
Jonathan Edwards just laid me bare in 1971 and '72 when I was reading his book Religious Affections. I can remember several nights where, in his chapter on evangelical humiliation, he began to peel back the onion layers of my soul.
He would say, "So you think you're humble? What if you're boasting in your humility?" And you admit, "Yes, I probably am boasting in my humility." And he would ask, "Well, what if your confession that you are boasting in your humility is really a pose, and you're still boasting in your humility?"
He gave question after question that made you realize, "There's no center to this onion." You peel and peel and peel, and the last peel just disappears, because you can always ask yourself, "How do you know?" You can always doubt yourself. There's no way, by mere self-analysis, to come to a point where you're looking at something that you can say, "Definitely authentic!" Because the capacity of the human brain to doubt is always there.
So where in the world does assurance come from? The answer is that, even though introspection is commended and wise up to a point, the bottom line of assurance comes when you stop analyzing and you look to Christ and you look and you look and you look until Christ himself in his glory and his sufficiency by reflex, as it were, awakens a self-forgetful "Yes!" to him.
Your best moments of assurance are not the moments when you're thinking about your assurance. Because the very moment that you're thinking about your assurance, you have the capacity at that moment to doubt your assurance. This little voice, whether it's your conscience or the devil, is saying, "You think you have assurance, but..."
And so the answer comes, "Look to the cross! Look to Christ!" And if you're able to look to the cross, if you're able to see him as sufficient and satisfying and powerfully able to carry all your sins, and you find yourself drawn out of yourself to say "Yes" to him, that's what you want. You are assured. He is your assurance at that moment.
The way Paul puts it in Romans 8 is that the Holy Spirit bears witness with our spirit that we are the children of God.
I deal with this problem probably more than any other problem when praying with people after services at Bethlehem. And my bottom-line answer to them is, "You know, I can tell you lots of things about why Christ is sufficient for you, and why your sins have not put you beyond the pale of forgiveness. But in the end it will be the work of God in your life, awakening you to see him as completely sufficient for you personally." And I think that's the witness of the Holy Spirit.
The Holy Spirit doesn't whisper in your ear, "You're a Christian," because you could doubt that voice, couldn't you? You could say, "I think that was my pizza last night," or "It was the devil." The witness of the Holy Spirit is not a whispering in your ear.
The witness of the Holy Spirit is the work of the Holy Spirit enabling you to look at Christ, feel him as your own, see him as precious, and say Galatians 2:20 personally: "I am crucified with Christ. It is no longer I who live, but Christ who lives in me. And the life that I now live in the flesh I live by faith in the Son of God who loved me and gave himself for me." It's that me that is the settling of our assurance.
Now, with regard to the unpardonable sin, I think the unpardonable sin is any sin that puts you beyond the capacity to do that.
If you can look to Christ and know him as your own, you haven't committed the unpardonable sin. The unpardonable sin is the sin that makes you an Esau. It brings you to a point where, according to Hebrews 12, Esau sought repentance, and he couldn't find it. He couldn't look away to Christ, renounce his sins, embrace Jesus, and rest in him as sufficient.
So my battle with somebody when they say that they've committed the unpardonable sin is not to say, "You haven't." I don't know! But I press them to look to Christ. I press them to fly to Jesus and pray for their eyes to be opened. And if God grants that prayer, then they haven't.
That's the litmus test, because the unforgivable sin is not any particular words, like "God damn you, Holy Spirit." There are people who have said those words at 13-years-old, when they got mad at their parents and just went back to their bedroom and said those words. And I say, "That's not it. It could be, but I don't think so." The question is, "Can you today renounce all the sins of your past and embrace Christ?"