2 Thessalonians 1:11

"With this in mind, we constantly pray for you, that our God may count you worthy of his calling, and that by his power he may fulfill every good purpose of yours and every act prompted by your faith." NIV translation

Paul continues to explain that he prays for the Thessalonians to walk in the Spirit and that God would use them. He knew that God had prepared things for them to do (see Ephesians 2:10) and prayed that God would complete the work that He had started.

2 Thessalonians 1:12

"We pray this so that the name of our Lord Jesus may be glorified in you, and you in him, according to the grace of our God and the Lord Jesus Christ." NIV translation

Paul tells us the purpose of his prayer and that is the same purpose that we all should have for everything that we do. That purpose is to glorify God which is to let people see His presence in and through us. That can only happen through the grace of God.