John 19:30 NLT Context
In this passage of the Gospel of John, we are shown that Jesus knew every single prophecy was complete.
John 19:30 NLT Meaning
The word finished here is the Greek word teleō, which means to pay (in full) or to fulfill or complete a command given.
The root word telos means to set out for a definite goal; it also translates to the uttermost.
So we are looking at the final words of Christ fulfilling what he promised to us, to the uttermost.
What did he promise?

Through Scripture, we can see that we are promised eternal life, full payment of our sins, complete healing, and an abundant life in the here and now.
Jesus paid for everything on the cross, so when he said, “It is finished,” he meant that everything that could possibly be paid for was paid for and done for us; now we only need to receive.
That abundant life described in John 10:10 is waiting for us; the Passion Translation says it this way: “But I have come to give you everything in abundance, more than you expect— life in its fullness until you overflow!”
John 19:30 NLT Application
We are meant to be overflowing in the fullness of life! Jesus paid for us to live free from the weight of sin, fear, doubt, worry, and so much more. We have fullness waiting for us as we simply receive.
In the middle of the storms of life, it can be difficult to be still and listen to the voice of our loving heavenly Father.
But I encourage you to sit back, take a deep breath, and hear the word of our Lord say to you, “My child, it is finished.”
“You will keep in perfect peace those whose minds are steadfast because they trust in you.”