It does seem odd, given the Apostle Paul’s exhortation in 1 Thessalonians 5:17–18 to “pray without ceasing” and to “give thanks in all circumstances,” that the Lord’s Prayer does not include instructions for thanksgiving. Furthermore, it seems especially odd seeing that Jesus models thanksgiving in prayer all throughout the gospels—in particular when He gives thanks to God so many times and in so many circumstances as He models prayer.
Jesus thanks God for the meals that He provides, including the miraculous feeding of the 5000 (Matthew 14:16–21) and the 4000 (Matthew 15:35–38). He gave thanks for the cup and the bread eaten at the Last Supper (Acts 27:35). He thanked God for hearing His request to raise Lazarus from the dead (John 11:41). He even thanked the Father from keeping the secrets of the kingdom from the wise and revealing them to the poor, the ignorant and the obscure (Matthew 11:25). Yet, He leaves thanksgiving out of the Lord’s Prayer.
Many of us were raised with the acronym ACTS (Adoration, Confession, Thanksgiving and Supplication) as a model for prayer. In other words, before we pray to God for our needs, we ought to praise Him for what He has done, confess our sins before Him, and offer thanks for His grace and mercy. When we look at the Lord’s Prayer, we see the A, C and S, but no T.
If we examine the passage in which we find the Lord’s Prayer (Matthew 6:9–13), we first note why Jesus was teaching the disciples to pray a certain way. Jesus was critiquing the way the Pharisees prayed. They prayed out in the open where all could see and hear. This was a way to show the public how holy and pious they were. Jesus condemns this way of praying by saying that “they have their reward,” the reward of being seen by men. Jesus is not condemning public prayer, only the practice of praying with the goal of being “seen by men.” We also see Jesus critiquing the way the Gentiles prayed by constantly praying the same thing over and over again as if to make sure their god heard them, such as the priests of Baal on Mount Carmel in 1 Kings 18.
Jesus’ corrective against these incorrect modes of prayer was to give His disciples a model prayer. Now, we don’t pray the Lord’s Prayer by simply reciting it as do the Roman Catholics and their rosary beads. This does not mean that corporate recital of the Lord’s Prayer is wrong. Jesus is, however, referring to private prayer, not corporate prayer.
It’s best to think of the Lord’s Prayer as a ‘blueprint’ for prayer—a means to shape and guide our prayer life. The prayer contains six petitions. The first three relate to God and the last three relate to us. After addressing God as “our Father in heaven,” we first pray that God’s name be made hallow (i.e., honored and glorified). Next we pray that God’s kingdom will come. There is a sense in which God’s kingdom is already present since the advent of Christ, but we pray for the kingdom to come in its fullness. Third, we pray for God’s will—His moral, or revealed, will—to be done here on earth, starting with us. After these three petitions which address God’s glory and majesty, we continue with the petitions that pertain to us—our daily provision, our forgiveness from sin and our deliverance from evil.
As for why we don’t find thanksgiving in the Lord’s Prayer, the best answer is that thanksgiving is the attitude and mindset in which we live, including when we pray to God. For those who are children of God, thanksgiving will fill our hearts and pour forth from our lips to God because we know, among other things, our sins are forgiven and we have eternal life through Jesus Christ. The more we contemplate what God has done for us, the more thankfulness just becomes a way of thinking in our relationship with God at all time, under all conditions and in all circumstances. Paul writes in 1 Thessalonians 5:18, “In everything give thanks, for this is the will of God in Christ Jesus concerning you.”
 Got Questions Ministries. (2010). Got Questions? Bible Questions Answered. Bellingham, WA: Logos Bible Software.