The Exchange.

One of the soldiers with a spear pierced his side, and immediately there came out blood and water.
Behold the blood of the covenant, which the Lord has made with you. — The life of the flesh is in the blood: and I have given it to you upon the altar to make an atonement for your souls. — It is not possible that the blood of bulls and of goats should take away sins.
Jesus said to them, This is my blood of the new testament, which is shed for many. — By his own blood he entered in once into the holy place, having obtained eternal redemption for us. — Peace through the blood of his cross.
You know that you were not redeemed with corruptible things, as silver and gold, ... but with the precious blood of Christ, as of a lamb without blemish and without spot. Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience.

One of the strangest things about Christianity, if you are outside looking in, is the idea of the communion service.  Jesus said to His disciples, "Take, eat, this is my body (the bread)"...and, "All of you drink of it (the wine), for this is my blood of the new covenant, which is shed for many." If you look at this as a rational person outside of Christianity, there is no way that you can logically understand why this works.  The reason is that it is the God-appointed way of dealing with our sins.  We cannot receive forgiveness for them, the Scriptures tell us, by doing good works.  No payment is ever enough.  So God devised a plan by which we can receive complete exoneration from all our sins, and be declared innocent--He sent His Son.  Why this works is a divine mystery, but how it works is laid out in the Scriptures from cover to cover.  God allowed His Son to accept the penalty for our sins by dying on our behalf.  

The Son of God replaced us, as it were, at the point of execution, and took the punishment we deserve.  This is good news for those of us who've sinned, and hard to take for those of us who think we are righteous, because we always are attempting to offer up our works in exchange for everlasting life.  God doesn't accept them. He accepts one thing--His own Son's (Jesus') righteousness, brought down into our lives by the simple act of believing that it is true, and that it is true for us.  "He who hears My (Jesus') word, and believes in Him who sent Me, has everlasting life, and shall not come into judgment, but has passed from death into life."

Explain it? Nobody can. Enjoy it and experience it? Anyone is welcome.

Peace of heart.

Isaiah 26:3: You will keep him in perfect peace, whose mind is stayed on you: because he trusts in you.

Peace of heart is an elusive thing. We talk about it in religious terms, and for the most part we believe that it's attainable--but quite often, we feel the stresses of life, the sorrows of life, the pressures that modern living brings. This verse, however, reveals that there is a discipline to living that does truly help, and that is to focus on God.  There are many times in the Psalms where David is terribly distressed, and he brings his troubles to the LORD.  After that, he finds rest in his soul, and his spirit is calmed.

For example:

David cries out in trouble (Psalm 3)
1 LORD, how they have increased who trouble me! Many are they who rise up against me. 

2 Many are they who say of me, " There is no help for him in God."
and then
4 I cried to the LORD with my voice, And He heard me from His holy hill.
5 I lay down and slept; I awoke, for the LORD sustained me.
The first verse describes how things are, and they are not very good. Even his acquaintances said, "He's finished." but David was not finished. The LORD strengthened him, and helped him.

There are numerous examples of this throughout the Psalms, and the process goes something like this:

TROUBLE...sometimes years of it.

PRAYER FOR HELP...and often real agony in life and prayer.

PEACE...

DELIVERANCE (but not always.  Sometimes the situations stay the same, and God's peace is His answer.

Phil. 4:6-7: do not be anxious about anything, but in everything by prayer and supplication with thanksgiving let your requests be made known to God. And the peace of God, which surpasses all understanding, will guard your hearts and your minds in Christ Jesus.

Psalm 73 is about a man of God who came to a crisis of faith because wicked wealthy men seemed never to experience the judgments of God in this life. They were always "fat and happy."  When he was done crying out to God, nothing had changed in the outside world, but his relationship to God had, because he saw that God was with him, and would be with him forever, and would guide him into heaven.  

It is sometimes like this. Things don't change, but we do, because He fills us with His peace and power, and sustains us in our way, even though times are very difficult for us. 

He offers you His peace.  Take it. Let your mind stop at God, and you will find His peace and sustaining strength, even when the times are hard.