Do you have sins in your past that haunt you.  Satan loves to throw them up to you and keep you on edge.  We must remember--at times when we are discouraged about past sin--what God has promised and not be weakened by that evil power.

In Hebrews 10:9 Paul compares God's old plan to the new: (I am quoting from the Living Bible) "Under this new plan, we have been forgiven and made clean by Christ's dying for us once and for all.  Under the old agreement, the priests stood before the altar day after day offering sacrifices that could never take away our sins.  But Christ gave himself to God for our sins as one sacrifice for all time... "

This works because of the Holy Spirit.  Paul explains:  vs16-17: "I will write my laws into their minds so that they will always know my will, and I will put my laws in their hearts so that they will want to obey them."  Wow.  No more tablets of stone!!  Isaiah summed it up when he prophesied in the Old Testament:   Isaiah 36:26  "A new heart also will I give you, and a new spirit will I put within you: and I will take away the stony heart out of your flesh, and I will give you an heart of flesh."

If you are a Christian, the desire to sin is gone.  You want to please God.  You have a new heart.  There isn't anything wrong with the ten commandments, but they just showed us how badly flawed we are.  I love the words, "...once and for all..."  and, "...one sacrifice for all time...".  Those words reassure us that we will never fall from God's grace.   If our our current sins caused us to be "lost" again, there was no point in Christ's death.  Instead, he would have to die over and over again.  Just like the old sacrifice of lambs, goats and doves.  "Once and for all," means what it says.

The Holy Spirit within us reminds us of what God expects.  And our new heart causes us to want to obey Him.  We are new creatures.  When we sin, our hearts are heavy.  We repent and don't do that  thing again.  If you keep doing the same sin over and over again, you need to worry.  If you have truly given yourself to Him, you won't do that.  You will keep short accounts with God.