God was in Christ, reconciling the world unto himself, not imputing their trespasses unto them. (II Cor. 5:19)
God has already forgiven the entire human race because of Jesus Christ. Because Jesus Christ has FINISHED His redemptive work, God is finished forgiving. And His forgiveness is total for every sin ever committed, or that will be committed.
Our faith does not contribute to this finished work. Nor can our unbelief subtract from it. It is a finished reality for us — regardless of whether we believe it or not. Thus, our faith doesn’t convince God to forgive us. Rather, by faith we embrace this Truth that He already has.
No one is really going to believe and embrace God’s finished forgiveness for them unless they know they need it. This is why we must be convicted of that need and brought to repentance and to the renunciation of the old life. Faith in Christ is not merely a religious doctrine to follow. It is the outcome of seeing the Truth of God in Christ.
The gospel of Jesus Christ states that in Christ God was reconciling the world to Himself – completely apart from our faith or works. That forgiveness is full and final in Christ. But only those who believe will be joined to the Lord and be saved by His life.