It would be good to define what the gospel is. The gospel means simply, “good news.” This “good news” consists of four basic parts: God, man, Christ, and response. In short, God created man (the 1st Adam) holy and upright, but man willfully plunged himself and the whole human race into sin through disobedience. Christ (the 2nd Adam) came to the Earth, lived and died in our place, for our sin and was resurrected. Because of this, human beings must respond in one way or another to the offer of forgiveness through Christ.
Sadly, the gospel of much of modern evangelicalism is “God loves you, and wants to give you purpose in life.” While that statement certainly contains elements of truth, it is not the gospel, nor is it the essential message of the Bible. When sharing the gospel with your children, your conversations must include that we were created righteous and rebelled against our Creator in selfishness. Our sin has separated us from God and we justly deserve His wrath. However, in His great love, God has to come us in Christ and paid the penalty for sin in His death on the cross. The resurrection of Christ assures us that God has accepted Christ’s work on our behalf. Now that God has provided a remedy for sin, we must respond in either rejection and unbelief or repentance and faith.
This is not a one-time conversation that has as its end goal a “decision for Christ,” but rather a whole way of talking about life and faith everyday in your home. When your children sin against another person, or they witness a sin in public (perhaps in the neighborhood or at school), or when they see their parents fight, these are all times ripe with opportunity to share the message of the gospel in word and in example with your children.
The gospel is a message of good news (forgiveness), because of some bad news (sin), that demands a response (repentance). This not just a conversation, but a lifestyle for families–a way of living before each other everyday.