How we cite our quotes:
Quote #1
For the people of those regions report about us what kind of welcome we had among you, and how you turned to God from idols, to serve a living and true God. (1 Thessalonians 1:9, NRSV)
For they themselves shew of us what manner of entering in we had unto you, and how ye turned to God from idols to serve the living and true God. (1 Thessalonians 1:9, KJV)
Paul praises the Thessalonians for ditching their idol-worshipping ways to follow Jesus. So that's one part of Christian identity down. No idol worship. Check.
Quote #2
For we know, brothers and sisters beloved by God, that he has chosen you, because our message of the gospel came to you not in word only, but also in power and in the Holy Spirit and with full conviction. (1 Thessalonians 1:4-5, NRSV)
Knowing, brethren beloved, your election of God. For our gospel came not unto you in word only, but also in power, and in the Holy Ghost, and in much assurance. (1 Thessalonians 1:4-5, KJV)
Another big part of Christian identity is this idea of chosenness. God selected these fine Thessalonian people to be his followers. How does Paul know? Because these guys believed him and have the Holy Spirit. Duh.
Quote #3
You remember our labor and toil, brothers and sisters; we worked night and day, so that we might not burden any of you while we proclaimed to you the gospel of God. You are witnesses, and God also, how pure, upright, and blameless our conduct was toward you believers. As you know, we dealt with each one of you like a father with his children, urging and encouraging you and pleading that you lead a life worthy of God, who calls you into his own kingdom and glory. (1 Thessalonians 2:9-12, NRSV)
For ye remember, brethren, our labour and travail: for labouring night and day, because we would not be chargeable unto any of you, we preached unto you the gospel of God. Ye are witnesses, and God also, how holily and justly and unblameably we behaved ourselves among you that believe: As ye know how we exhorted and comforted and charged every one of you, as a father doth his children, That ye would walk worthy of God, who hath called you unto his kingdom and glory. (1 Thessalonians 2:9-12, KJV)
Paul's own identity is also a big deal here. He sees himself as essentially a hard worker. He's not trying to lead anyone astray or mooch off his congregation. Not only that, but Paul treats these "kids" like he's their dad. Taking care of them, nurturing them, and making sure they don't stay out past curfew.