Summary: Jesus spoke seven statements from the Cross-, each statement showing a different aspect of Calvary’s function. The first three statements (which we call "words") were spoken before Jesus entered the court of God:
The justice of God was satisfied at Calvary when Christ paid the penalty for our sins on the Cross. The mercy of God was satisfied at Calvary because we did not have to suffer the penalty of sin, a penalty we so richly deserved.
Jesus spoke seven statements from the Cross-, each statement showing a different aspect of Calvary’s function. The first three statements (which we call "words") were spoken before Jesus entered the court of God:
Words of Forgiveness (God forgives)
Then said Jesus, Father, forgive them; for they know not what they do. And they parted his raiment, and cast lots.
Words of Promise (He keeps his promises)
And Jesus said unto him, Verily I say unto thee, To day shalt thou be with me in paradise.
And if Christ be in you, the body is dead because of sin; but the Spirit is life because of righteousness.
For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord.
But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us.
Words of Care (We have responsibilities)
When Jesus therefore saw his mother, and the disciple standing by, whom he loved, he saith unto his mother, Woman, behold thy son!  Then saith he to the disciple, Behold thy mother! And from that hour that disciple took her unto his own home.
With these three words Jesus saw that all His earthly responsibilities were cared for, offered forgiveness to those who did not deserve such forgiveness, and welcomed a new convert into the Kingdom of God.
Words of Loneliness (Living in the World)
And about the ninth hour Jesus cried with a loud voice, saying, Eli, Eli, lama sabachthani? that is to say, My God, my God, why hast thou forsaken me?
In Christ’s fourth word He entered the courtroom of God. Jesus usually addressed the head of the Trinity as "Father", but He now calls Him "God", a judicial title rather than the familial one.
Words of Suffering (Life without Christ)
After this, Jesus knowing that all things were now accomplished that the scripture might be fulfilled, saith, I thirst.
In Christ’s fifth word He gives evidence of His suffering in the flesh of His humanity. Between the word of loneliness and the word of suffering Jesus paid the price for our sins. The punishment was so complete a retributive that the earth was darkened during that time, a period of about three hours (Luke 23.44).
Words of Triumph (Through Salvation)
When Jesus therefore had received the vinegar, he said, It is finished: and he bowed his head, and gave up the ghost.
Words of Trust (Through Living in Christ)
And when Jesus had cried with a loud voice, he said, Father, into thy hands I commend my spirit: and having said thus, he gave up the ghost.
In the last two words Jesus uttered we see Him emerge from the courtroom of God, not a defeated man, but triumphant as our Savior. When He said, "It is Finished", He declared that the work was acceptable to God, that we need not fear our eternal status because Jesus finished the work for us. Having finished the work Jesus commended His earthly life to God. Not forever, as Buddha and Mohammed did, but for but three days. But that is another doctrine.