@shalom
The word Eucharist comes from the Greek verb eucharisteo which means to give thanks, a present active indicative in the Gospels that shows deliberate, ongoing, chosen gratitude that Jesus performs in real time while walking toward the cross, and the moment you insert that verb into the narrative the whole scene in the upper room opens with blazing clarity because He chooses thanksgiving in the very hour He prepares to be delivered over to judgment as the Lamb of God who takes away the sin of the world.
In ~Matthew 26:27 we read and having taken the cup and having given thanks, eucharistesas, He gave it to them saying Drink of it all of you, which means that the entire action of the cup is framed by deliberate thanksgiving in the face of suffering, and again in ~Luke 22:19 the text says and having taken bread and having given thanks, eucharistesas, He broke it and gave it to them saying This is My body being given for you, do this in remembrance of Me, where the Greek verb didomenon is a present passive participle that paints the Messiah as the One being given over for the redemption of sinners.
The Hebrew background reinforces this pattern because the act of thanksgiving in the Old Testament is todah, a thank offering that often involved sacrifice as seen in ~Psalm 50:14 and the entire movement of the todah offering anticipates the Messiah who will offer Himself once for all on the cross, therefore Jesus is not simply praying a blessing, He is fulfilling the entire sacrificial pattern by giving thanks as He becomes the offering.
Your observation is right that this transforms the Lord’s Supper because the early church understood that they were not merely repeating a ritual but stepping into an act of thanksgiving shaped by the cross, which is why ~Acts 2:42 says they were continually devoting themselves to the breaking of bread and to the prayers, a present durative verb that shows the early believers lived in a rhythm of ongoing remembrance and gratitude anchored in the crucified and risen Lord.
The apostle Paul preserves this when he writes in ~1 Corinthians 11:23 through 26 that on the night He was betrayed He took bread and gave thanks, eucharistesas, and Paul frames the whole moment by the cross, saying For as often as you eat this bread and drink this cup you proclaim the Lord’s death until He comes, where the verb katangellō, proclaim, is present active indicative showing that the act of communion is a continual proclamation of the crucifixion.
Your conclusion that thanksgiving becomes the anchor of the practice is fully consistent with Scripture because the shape of Christian worship is gratitude flowing out of the cross where Christ triumphed over sin and death, for this reason Paul connects eucharisteo directly to the will of God in Christ Jesus in ~1 Thessalonians 5:18 saying In everything give thanks, for this is the will of God for you in Christ Jesus, and all of this is grounded in the once for all offering of the body of Christ described in ~Hebrews 10:10.
So the point is clear and scriptural that Eucharist means thanksgiving and the thanksgiving is not sentimental but cruciform, not shallow but purchased by blood, not a ritual but a living remembrance that Christ Jesus gave thanks in the hour He was betrayed and His people give thanks whenever they remember His sacrifice, His body given, His blood poured out, and His resurrection that breaks the power of death.
New Testament
The major word used for thanks and thanksgiving (some references)
eucharisteō (cf. 1 Cor. 1:4,14; 10:30; 11:24; 14:17,18; Col. 1:3,12; 3:17)
eucharistos (cf. Col. 3:15)
eucharistia (cf. 1 Cor. 14:16; 2 Cor. 4:15; 9:11,12; Col. 2:7; 4:2)
charis (cf. 1 Cor. 15:57; 2 Cor. 2:14; 8:16; 9:15; 1 Pet. 2:19)
The example of Jesus
He was thankful for food:
(1) Luke 22:17,19 (1 Cor. 11:24)
(2) John 6:11,23
He was thankful for answered prayer, John 11:41
Other examples of thankfulness
For God’s gift of Christ, 2 Cor. 9:15
For food
(1) Acts 27:35
(2) Romans 14:6
(3) 1 Corinthians 10:30; 11:24
(4) 1 Timothy 4:3-4
For healing, Luke 17:16
For peace, Acts 24:2-3
For deliverance from danger
(1) Acts 27:35
(2) Acts 28:15
For all circumstances, Philippians 4:6
For all humans, especially leaders, 1 Timothy 2:1-2
Other aspects of thankfulness
It is God’s will for all believers, 1 Thessalonians 5:18
It is an evidence of the Spirit-filled life, Ephesians 5:20
To neglect it is sin
(1) Luke 17:16-17
(2) Romans 1:21
It is an antidote for sin, Ephesians 5:4
Paul’s thankfulness
His blessings on the church
(1) for proclaiming the gospel
(a) Romans 1:8
(b) Colossians 1:3-4
(c) Ephesians 1:15-16
(d) 1 Thessalonians 1:2
(2) for grace bestowed
(a) 1 Corinthians 1:4
(b) 2 Corinthians 1:11; 4:15
(3) for accepting the gospel, 1 Thessalonians 2:13
(4) for fellowship in the spread of the gospel, Philippians 1:3-5
(5) for growth in grace, 2 Thessalonians 1:3
(6) for knowledge of election, 2 Thessalonians 2:13
(7) for spiritual blessings, Colossians 1:12; 3:15
(8) for liberality in giving, 2 Corinthians 9:11-12
(9) for joy over new believers, 1 Thessalonians 3:9
His personal thanksgiving
(1) for being a believer, Colossians 1:12
(2) for deliverance from bondage to sin, Romans 7:25; 2 Cor. 2:14
(3) for the sacrificial labor of other believers, Romans 16:4; 2 Cor. 8:16
(4) for some acts not occurring, 1 Corinthians 1:14
(5) for personal spiritual gift, 1 Corinthians 14:18
(6) for the spiritual growth of friends, Philemon 4-5
(7) for the physical strength for ministry, 1 Timothy 1:12
Conclusion
Thanksgiving is our central response to God once we are saved. It issues not only in verbal assent, but lifestyle gratitude.
Thanksgiving in all things is the goal of a mature life in the care of God ( cf. 1 Thess. 5:13-18).
Thanksgiving is a recurrent theme of both Old and New Testaments. Is it a theme of yours?
Would love to meet your pastor, you are in good company.
J.