An excerpt from chapter three of John Piper’s Future Grace, entitled “Faith in Future Grace vs. Anxiety”:
“There is another possible response to the truth that our anxiety is rooted in our failure to live by faith in future grace. It goes like this “I have to deal with feelings of anxiety almost every day; and so I feel like my faith in God’s grace must be totally inadequate. So I wonder if I can have any assurance of being saved at all.”
My response to this concern is a little different. Suppose you are in a car race and your enemy, who doesn’t want you to finish the race, throws mud on your windshield. The fact that you temporarily lose sight of your goal and start to swerve, does not mean that you are going to quit the race. And it certainly doesn’t mean that you are on the wrong race track. Otherwise the enemy wouldn’t bother you at all. What it means is that you should turn on your windshield wipers and use your windshield washer.
When anxiety strikes and blurs our vision of God’s glory and the greatness of the future plans he has for us, this does not mean that we are faithless, or that we will not make it to heaven. It means our faith is being attacked. At first blow, our belief in God’s promises may sputter and swerve. But whether we stay on track and make it to the finish line depends on whether, by grace, we set in motion a process of resistance–whether we fight back against the unbelief of anxiety. Will we turn on the windshield wipers and we will use our windshield washer?
Psalm 56:3 says “When I am afraid; I put my trust in three.” Notice: it does not say, “I never struggle with fear.” Fear strikes, and the battle begins. So the Bible does not assume that true believers will have no anxieties. Instead the Bible tells us how to fight when they strike. For example, 1 Peter 5:7 says “Cast all your anxieties on Him, for He cares about you.” It does not say, you will never feel any anxieties. It says, when you have them, cast them on God. When the mud splatters your windshield and you temporarily lose sight of the road and start to swerve in anxiety, turn on your wipers and squirt your windshield washer.
So my response to the person who has to deal with feelings of anxiety every day is to say: that’s more or less normal. At least it is for me, ever since my teenage years. The issue is: How do we fight them?
The answer to that question is: we fight anxieties by fighting against unbelief and fighting for faith in future grace. And the way you fight this “good fight” is by meditating on God’s assurances of future grace and by asking for the help of his Spirit. The windshield wipers are the promises of God that clear away the mud of unbelief, and the windshield washer fluid is the help of the Holy Spirit. The battle to be freed from sin, as we have seen, is “by the Spirit and by faith in the truth” (2 Thess 2:13). The work of the Spirit and the Word of the truth. These are the great faith builders.
Without the softening work of the Holy Spirit, the wipers of the Word just scrape over the blinding clumps of unbelief. Both are necessary–the Spirit and the Word. We read the promises of God and we pray for the help of his Spirit. And as the windshield clears so that we can see the welfare that God plans for us (Jer 29:11), our faith grows stronger and the swerving anxiety smooths out.”