Over the past few weeks we’ve been exploring doubt and considering what causes it to arise within the life of the believer. As someone who’s spent 20 years studying philosophy and apologetics, you might expect me to say that doubt is purely an intellectual matter. I do believe that much of our doubt comes from a lack of intellectual flourishing or from tough intellectual questions that we face. But, intellectual factors are not the only factors that cause doubt. So what else is going on?

At the risk of sounding like I am over spiritualizing it, I must note that sin is often a major factor. When we allow sin to remain in our lives, doubt often springs up to squelch our faith. And once we being to struggle with our faith, a greater tendency towards sin arises. It’s a vicious cycle that spins out of control until, for some, faith is lost completely. But how, exactly, is it that sin breeds doubt? Let me mention just two ways.

First, sin quenches the Holy Spirit. When we allow sin to take root in our lives, we isolate ourselves from the Holy Spirit. As Christ taught in John’s gospel, the Holy Spirit graciously brings conviction of sin, strength to fight spiritual battles, and comfort in moments turmoil. The Holy Spirit nurtures us and guides our minds towards Christ. Without Him, our minds are prone to wonder and doubts are far more likely to emerge.

Second, lingering sin makes us far more likely to be blinded by pride and arrogance. When pride takes root, we elevate our own minds and our own thinking. We forget the frail condition of our fallen minds and stop seeking and listening to sound reason. And it doesn’t take long until something comes along that fractures the foundations of our weak thinking, leaving us to doubt and question what we once found to be so strong.

Yes, sin causes doubt. I’ve seen this in my own life, and I’ve seen it in the life of my friends and my students. We might like to pretend it’s not so, but sin cuts us off from the Holy Spirit’s protective grace and leaves us to flounder in doubt.

So what do we do? In short, don’t forget the lessons we first learned as followers of Christ. Check yourself…regularly! Remember I John 1:9. “If we confess our sins, He is faithful and just to forgive us and cleanse us from all unrighteousness.” Fight for purity in all aspects of life. Repent when you sin and be diligent to root out sin where it springs up in your life.

Otherwise, sin runs its course and leaves doubt in its path. It’s happened to me. It’s happened to many of my friends. Don’t let it happen to you. But if it does, or if it has, remember that grace can renew you again!