I want you to imagine something.
We sometimes have difficulty looking ourselves in the mirror because of the shame we feel because of the bad things we have done.
Imagine being brought before someone who knows everything about you. And when I say knows everything about you, He knows absolutely every thought and desire you have ever had. Not in some sort of faded memory kind of way. He has the kind of mind where everything you have ever wanted, everything you have ever thought, it is right there in front of Him perfectly.
And what is more He is absolutely pure. This is someone you look at and besides the fact that He is awesome, huge, powerful, massive, you see Him and you know He is perfection. You know the feeling you get when you see something that just seems so right, take that feeling and multiply it by infinity. This person knows everything about you, and this person is absolutely glorious and right.
Now take this one step further, imagine being able to stand before a person like that. And not just stand but to be confident before a person like that. And not just that, but to be fully assured before a person like that. Not quivering because you think He might see something.
That is a clean conscience.
This is not just having a group of friends who approve of you and what you have done. This is having someone who actually matters and someone who knows everything that you have done, approve and not just having Him approve but being fully assured of that approval and the writer of Hebrews says that those who are believers in Jesus Christ have just that because of the work of Christ on the cross on their behalf!
“When Christ appeared as a high priest of the good things to come, He entered through the greater and more perfect tabernacle, not made with hands, that is to say, not of this creation; and not through the blood of goats and calves, but through His own blood, having obtained eternal redemption. For if the blood of goats and bulls and ashes of a heifer sprinkling those who have been defiled, sanctify for the cleansing of the flesh , how much more will the blood of Christ who through the eternal Spirit offered himself without blemish to God, cleanse your conscience from dead works to serve the living God.”
John Piper explains what is going on like this,
“All throughout the Old Testament conscience was an issue. But the animal sacrifices themselves could not cleanse the conscience. Hebrews 9:9 and 10 explains, ‘Gifts and sacrifices are offered that cannot perfect the conscience of the worshiper, but deal only with food and drink and various washing, regulations for the body imposed until the time of reformation.’ As a foreshadowing of Christ God counted the blood of animals as sufficient for cleansing the flesh – the ceremonial uncleanness, but not for the conscience. No animal blood could cleanse the conscience. They knew it and we know it. So a new high priest comes – Jesus the Son of God – with a better sacrifice: himself. Hebrews 9:14, ‘How much more will the blood of Christ, who through the eternal Spirit offered himself without blemish to God, purify our conscience from dead works to serve the living God.’”
That’s a reason for confidence!
Or as the writer of Hebrews puts it,
“Since therefore brethren we have confidence to enter the holy place by the blood of Jesus, by a new and living way which He inaugurated for us through the veil, that is, His flesh, and since we have a great high priest over the house of God, let us draw near with a sincere heart in full assurance of faith, having our hearts sprinkled clean from an evil conscience and our bodies washed with pure water.”