No human meets God's standard of perfection. Only Jesus does. When you trust Christ's sacrifice, God sees His perfect righteousness covering you instead of your sin. Salvation is a free exchange: your imperfect record for His.
Who among us walks in such perfection that we meet God's standard? None of us. Who's the only one who ever walked in such perfection as to meet God's standard? Well, it's the Lord Jesus, of course. So when you stand before God and you hear, well done, good and faithful servant, that's not because of the work you did. It's because of the work Christ did. It's not about your performance. It's about his perfection. And in order for you to trade your performance for his perfection, You need faith in His perfection. You need faith in what He did on the cross. So by faith, we exchange records with Christ when we accept the free gift of salvation, so that when God looks at us, He sees His Son, Jesus. And when God looks at the cross, He sees your sin.
