This Psalm is about how God receives a perfect person. Once, knowing I could not be perfect, I was comforted that Jesus stood in God's presence for me. That was fine, but the gospel gives us much more than a mediator. Because of Jesus' perfect sacrifice I am redeemed and God sees me as perfect.
This Psalm is about how God receives me; this Psalm is about how God receives everyone who has put their faith in him. This Psalm is about how God receives you, not because of anything you've done, beloved, but because of what he has done.