We’ve been going through an old list of questions and answers contained in the Westminster Larger Catechism published in the 17th century. We’ve seen that the mediation of Jesus brings justification, which is a legal declaration that you are right before God, despite your sinfulness. We also saw that this justification only happens by faith in Christ. But how are people brought to this justifying faith?
The faith that justifies is brought about in the heart of a sinner by the Word of God. Paul explains in his letter to the church in Rome:
‘4 Christ is the end of the law so that there may be righteousness for everyone who believes.  
5 Moses describes in this way the righteousness that is by the law: “The man who does these things will live by them.”  6 But the righteousness that is by faith says: “Do not say in your heart, ‘Who will ascend into heaven?’ ” (that is, to bring Christ down)  7 “or ‘Who will descend into the deep?’ ” (that is, to bring Christ up from the dead).  8 But what does it say? “The word is near you; it is in your mouth and in your heart,” that is, the word of faith we are proclaiming:  9 That if you confess with your mouth, “Jesus is Lord,” and believe in your heart that God raised him from the dead, you will be saved.  10 For it is with your heart that you believe and are justified, and it is with your mouth that you confess and are saved.  11 As the Scripture says, “Anyone who trusts in him will never be put to shame.”  12 For there is no difference between Jew and Gentile–the same Lord is Lord of all and richly blesses all who call on him,  13 for, “Everyone who calls on the name of the Lord will be saved.” 

14 How, then, can they call on the one they have not believed in? And how can they believe in the one of whom they have not heard? And how can they hear without someone preaching to them?  15 And how can they preach unless they are sent? As it is written, “How beautiful are the feet of those who bring good news!”  
16 But not all the Israelites accepted the good news. For Isaiah says, “Lord, who has believed our message?”  17 Consequently, faith comes from hearing the message, and the message is heard through the word of Christ.  (Rom 10:4-17)’
Notice what Paul says in verse 4, righteousness is available through Christ for everyone who believes. And then after speaking about the way this faith is demonstrated, Paul says in verse 17 that such faith comes from hearing the word of God.
So without the word of God, no one can believe in Jesus. Which makes sense. You can’t believe in something if you’ve never heard of it. For example, you can’t believe that the Prime Minister exists if you’ve never heard of him. So it is with Jesus, you can’t believe in Jesus unless you hear about him.
So the word of God is essential to having justifying faith. It is only in the Word of God that we can truly know about Jesus and put our faith in him.
Sadly many people do not hear about Jesus and so do not believe and are not justified.
Will you listen to the Word of God, believe and be justified?
Joel Radford