Psalm 51:1-2
Have mercy upon me, O God, according to thy lovingkindness: according unto the multitude of thy tender mercies blot out my transgressions.  Wash me throughly from mine iniquity, and cleanse me from my sin.

Sin is a stain upon our lives that affects us in many ways.  For a time, David had been blind to what he had done, but it had been affecting him all the while.  And when the realization comes, he is desperate for forgiveness, mercy, and cleansing.  It is uncomfortable to be dirty, and to live in that state degrades us continually until we are finally cleansed.  Especially as God’s children, when we are saved and have that special relationship with God, that undealt-with sin mars our life, our relationship, and our well-being.

When we sin, we have no appeal we can make except to God’s love and God’s mercy.  Nothing at all within us would warrant Him even looking our way, let alone granting pardon.  When we have repaid His goodness with some wretched sin, we deserve His wrath, but He shows us kindness.  His mercy is great.  His grace is abundant.  And when our hearts, full of true sorrow and repentance, plead before Him, He cleanses us completely, leaving no remnant at all of the black stain sin had placed upon us.  His mercy is that cleansing flood that makes us truly and wholly clean.

And as deeply and as thoroughly as our sin was ingrained within us, as much as it was able to affect every part of us, God’s grace comes in and makes us thoroughly new and wipes away our sin as if it never existed at all.  No matter how low sin has brought us, His love can take us higher.  No matter how wretched we felt and how wretched we knew ourselves to be, His mercy can give us the peaceful mind of His own redeemed child.  And there is no sin that is out of God’s reach, for His forgiveness covers a multitude of sins.

Sin makes us unclean and tarnishes us in God’s sight.  It pulls us away from Him because He cannot tolerate sin, so perhaps the most amazing part of it all is that God is willing to forgive us.  He is willing to take away our sin.  He is willing to show mercy to us.  He deals with us in such a tender way when we sit before Him in our shame and sorrow.  And His grace is always bigger than whatever we have done.  Let us go to Him, then, for that complete and thorough cleansing that takes away every blot and stain upon us.