When Jesus therefore had received the vinegar, He said, “It is finished:” and He bowed His head, and gave up the ghost.
The Jews therefore, because it was the preparation, that the bodies should not remain upon the cross on the Sabbath day, (for that Sabbath day was an high day,) besought Pilate that their legs might be broken, and that they might be taken away. Then came the soldiers, and brake the legs of the first, and of the other which was crucified with Him.  But when they came to Jesus, and saw that He was dead already, they brake not His legs: but one of the soldiers with a spear pierced His side, and forthwith came there out blood and water.  And he that saw it bare record, and his record is true: and he knoweth that he saith true, that ye might believe. For these things were done, that the Scripture should be fulfilled, “A bone of him shall not be broken.” And again another Scripture saith, “They shall look on Him whom they pierced.”
John 19:30-37

The words of Jesus which He spoke from the cross are about seven.  The one in verse thirty is about the last words Jesus spoke.  It was probably next to last with His, “Father, into Your hands I commit My spirit” (Luke 23:46), being His final words from the cross.

What was it that Jesus was saying “It is finished” about?

1.  He had finished the work the Father had given Him  to do;
2.  He was diligent in doing the will of  God in the fulfilling of prophecy;
3.   He lived the  life God the Father desired His Son to live;
4.  He finished fulfilling the prophecies of Scripture concerning the sacrifices, and offerings, and of the tabernacle in the wilderness; and
5.  The work of the priesthood was completed, in that since Jesus was raised up from the grave He has an everlasting Priesthood.

I am fairly certain that this list is not exhausted.

When Jesus said , “It is finished”, He was telling us the sin debt was paid in full.  Those who come to Him will never perish.