My humble effort is this:
God, who loves us, gave us the bible so that we might hear, understand and welcome the good news about Jesus Christ, and through this “gospel” escape eternal condemnation, receive instead forgiveness for our sins, become transformed and empowered by God’s spirit to do good and not evil, get adopted into the family of God, and enjoy, for eternity, with all the saints, the unsurpassed glory of our incredible God.
Not exactly snappy, I know. That number of commas in a sentence kind of makes me gag.
I found that I had to think of the bible in terms of what it means to people: what is achieved, rather than how it is achieved. The “how” is the gospel. The gospel of Jesus Christ is the central means by which God achieves all these things. The how is what we are getting our heads around as we read it.
This exercise is difficult, because it makes us think about how readers might misunderstand, or be allowed to continue in error because of what we omit. If I were to put it in slightly more cryptic sentence, I might say:
The bible is there to explain to us what God has achieved (for himself and for us) and how he has achieved it.
But I’m not as happy with that, to be honest! How do you excite interest in the listener? How do you help them remember? Awareness of these things are vital in communicating vital truth, and we ought to take this seriously. The bible itself reveals God’s methods in communicating to a fallen humanity.
1 In the past God spoke to our ancestors through the prophets at many times and in various ways, 2 but in these last days he has spoken to us by his Son, whom he appointed heir of all things, and through whom also he made the universe. (Hebrew 1:1-2)
It’s a good exercise to meditate on these things. If you can know the answer, then it’s actually not that far a step to be able to say to a friend: “what do you think the bible is about?”
If you’re doing the B2Y with us, why not give it a try in the comments section? What is the message of the bible, in one sentence?