The heart will let us down: however faith gives us assurance of salvation
Every way of a man is right in his own eyes, But the LORD weighs the hearts.
"The heart is deceitful above all things, And desperately wicked; Who can know it?" (Jeremiah 17:9)
Therefore, brethren, having boldness to enter the Holiest by the blood of Jesus, by a new and living way which He consecrated for us, through the veil, that is, His flesh, and having a High Priest over the house of God, let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience and our bodies washed with pure water.