No one is interested in a pardon unless he has been convicted. Offering a sinner a pardon for sins before the sinner has been convicted is foolish. If a sinner does not see himself as a sinner condemned under the law, he will not be interested in receiving the free pardon in Christ Jesus.
When we talk to a sinner, we must first convict the sinner under the law. Once the sinner sees himself guilty before God and condemned to Hell, then we can offer the grace of God found in the free pardon received through faith in the Lord Jesus Christ.