“Thanks be to God for his indescribable gift!”
If we were looking for a person who exemplified what it means to be thankful, the person who is cleansed from leprosy—the Samaritan—would be a good choice.
There were ten lepers, as we are told.  It’s a very simple passage, this passage from Luke’s gospel—deceptively simple, one could say, because, behind the simplicity, there are elements which don’t quite fit, or suggest a depth beyond what is obvious.
So ten lepers are cleansed.  However, first of all, the lepers come to Jesus, and call on him to have mercy on them.  They do so at a distance, because lepers, at that time, or people with some sort of skin condition, were not to approach others, but to dwell at a distance, so as not to make other people unclean.
Well, the ten called out at a distance, “Master, have mercy upon us!”  Jesus said, “Go and show yourselves to the priests.”  Now, those words—they leave something out, of course.  They leave out the whole business of, “You will be cleansed” or “you will be healed en route.”  Simply, Jesus says, “Go and show yourselves to the priests.”
And, of course, if you read the book of Leviticus of the Old Testament, you find that, indeed, people suffering from such skin conditions were obligated to go to the priests and show whether or not they had been cured of their leprosy, at which point they would included back into the worshipping community and the social fabric of the people of Israel.
There is a problem not only with Jesus’ words—what they do not say.  There is a problem also because one of these individuals, one of the ten, does not happen to be Jew.  He, in fact, is a Samaritan.  So it would not be any good to him to go to try and show himself to the priests—at least not to the priests in Jerusalem—because he was not one of them.  He would not be accepted there; by his very identity as a Samaritan, he would be considered “unclean”, not a person to be included in the worshipping community of Israel.
But it’s this Samaritan, who has this terrific insight, after he realizes that he has been healed on the way.  He realizes that there were unspoken words of Jesus, unspoken words which, in fact, addressed him, words such as, “You will be healed; you are healed.”  And, so, this person had the insight that God had blessed him; and he knew, furthermore, where this blessing came from—namely, in the person of Jesus.  So he decided, right away, to turn around, and return to Jesus to offer thanks to him.
So, insight was part of this Samaritan’s response.  And insight is a part of the nature of thanksgiving.  By thanksgiving, we realize that we have been blessed, something good has been done for us, and we act accordingly, as a consequence of that insight, especially when we know where the blessing has come from.  And, ultimately, it’s a question of faith.  Like the Samaritan, we may be those who realize we have been blessed.  God has addressed us with his perhaps unspoken Word.  It has found its way into our heart and mind, and we respond.
It’s not always the case, as we know, in our own lives, or in the lives of others.  There are some times when we do not realize when we have received.  We do not realize when other people have done something special for us; or another person has done something special for us.  We simply take it for granted.
Strange to say—those other nine may have been in that category; we don’t really know.  But we do know, from the passage, that the Samaritan had that insight, that awareness, that came from receiving God’s address to him, through Christ, which called for his response.
So, a first element, one could say, of thanksgiving is this awareness that you have been blessed, that a person or God has reached out to you and touched you, made you well in some way or another.
This Samaritan, by the way, was able to ignore those words of Jesus, that he was to go and show himself to the priests, because there was a more important word that he heard, deep within his heart and mind, which called him to turn around.
Now, as we look further in this passage, it’s important to observe another aspect of thankfulness—that is, its joyfulness.  When the Samaritan realized what had happened, he cried out in a loud voice, and then, when he returned to Jesus, he fell at Jesus’ feet, and thanked him—there is the sense of great joy as part of his life.
Now—another odd word of Jesus, in connection with this, is to remark that, “Is this the only one to return, this foreigner?”  He uses that word “foreigner” which sounds very much like a put-down.  But what was taking place was anything but alienation or lack of welcome.  Instead, this person found in Jesus one through whom he was being included.  He was no Jew; he was a Samaritan; but he found himself now included in the very family and kingdom of God.
So, the emotional aspect of thankfulness is also an important one.  And we can express that in quite a variety of ways.  We can express it by our praise of God, which shows joy.  We can express it also by the way in which we reach out to others, and seek to include them.
Thankfulness has this emotional dimension, in addition to the dimension of the realization that something good has come to us, particularly something good that has come to us from God.
This emotional quality to our faith arises from the fact that this gift that has been given to us is no ordinary gift.  It is a gift that the apostle Paul calls “indescribable”.  It is a gift which has a quality which cannot even be narrated or spoken of, in its entirety.  It is so vast.  It is so wonderful.  It’s being included in the family of God, and therefore, it means joy and expressing that joy.
Now, the Samaritan, as well as coming to a realization of what had happened to him, of expressing all of that with great joy, in a very physical way, also received a bit of direction from Jesus, at the end of the passage.  According to the passage, what Jesus said to the man is this, “Get up, and go on your way.  Your faith has made you well.”
Now, in the temple worship of Israel, it was the custom that you brought an offering when you had been healed—whether it was a dove or a pigeon, some such offering—to the temple, as part of your worship.  That was your way of saying thanks to God.
However, no such offering is mentioned in this passage.  Instead, it’s very simple:  “Get up, and go on your way.  Your faith has made you well.”  As a result of encounter with the living God, as he has made himself known in Jesus Christ, there is a permanent gift given—shall we say—to this individual.  It is the gift of faith, faith, which is a reorientation of one’s life to God; and it’s a faith which is not limited by a whole series of offerings that one might be obligated to make, such as a turtledove or a pigeon, some such creature.  Instead, this faith gives us the freedom to be creative in the way we give thanks to God, in our service in the world, in our service of neighbour.  There is no limit, in some way, to how we can thank God.  But it is an active thankfulness into which we are called.  We are to go our way, and be guided by this faith, this Spirit, Spirit of God, who accompanies us, who guides us on our way, and calls us to creativity in the way in which we offer our thanks.
So, thankfulness is realization, a realization, when it comes to our relationship with God, a realization of God’s impact, God’s drawing-near to us in the person of Christ.  Thanksgiving involves this response of joy, because of the “indescribable gift” that has been given us, of being included in the family of God.  Thankfulness also acts out of this faith, this Spirit, the Holy Spirit, whom we have been given, whereby we can be creative in ways in which we can serve God—not limited to set offerings, but in all sorts of ways serve God, and so be thankful.
Thankfulness was given to that individual, the Samaritan, the outsider, whom Jesus even referred to as “a foreigner”, a person who could not offer gifts according to the prescribed way for lepers, who had become healed.  But that leper showed the way that was to come, the way of faith in Jesus Christ, the way in which all of us can walk, as we realize what God has done for us, respond in joy, and are creative in following the gift of faith, the way of the Spirit, in serving God in the world, amongst ourselves, and beyond.