Unbelief is the root of all sin and unlove.

Belief in the promises of God is the root of all love.

Therefore, beneath the target of love is the target of faith.

We must gather together to strengthen each other's confidence in the promises of God.

Why is it essential that we as Christians fight together for faith in God's promises?

That's the question John Piper answers from Hebrews 3, 12 to 14 in this episode of Light and Truth.

This sermon was originally preached at Bethlehem Baptist Church on September 18, 1988.

I survive in the ministry and thrive as a Christian because I'm surrounded by people who pray for me and who give me personal, regular, exhortation and encouragement from the Word of God.

I got a postcard two weeks ago from a pastor who ministered to me and strengthened my faith.

Let me use it as an example of the kind of thing that can happen both through the mail and more importantly face to face.

He didn't even address it to me except on the front side of the postcard so it would arrive at the church.

It was dear Lord and it was a prayer for me to read. I'll read you part of it. Dear Lord, glorify yourself our Savior by moving us as a family of believers to pray as never before.

May we find delight and enrichment in new intimacy of conversation with you. May our churches experience new health and vitality.

And grant us by a fuller liberation of your power through mighty multiplied intercession to capture the strongholds of darkness in our country and around the world.

That your name will everywhere be esteemed and revered. Give special guidance to your servant John as he wrestles with the discernment of urgent issues for Bethlehem's future.

Even in uncertainty provide such inner confidence of your ultimate leading that his peace will be unspeakable and unshakable your servant bill.

So it can happen through the mail and it can happen face to face. It ought to happen face to face regularly.

Last week what we saw was that the name of the game or the top priority in Christian living is to battle unbelief.

That is the most important job we have. Battling unbelief, that's the negative way of saying it, or fighting the fight of faith. That's the positive way of saying it.

Now the Apostle Paul lived his life this way. One of the most important texts that I'm going to come back to probably dozens of times in the next 13 weeks is 2 Timothy 47.

Let me just read it to you. Paul is at the end of his life. This is probably the last letter he wrote. He said, I have fought the good fight.

I have finished the course. I have kept the faith, fought the good fight, kept the faith. What is the fight? It's the good fight of faith.

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