God's will

Acts 7:51
Ye stiffnecked and uncircumcised in heart and ears, ye do always resist the Holy Ghost: as your fathers did, so do ye.

1 Thessalonians 4:3
For this is the will of God, even your sanctification, that ye should abstain from fornication:

This is not a command, it rather is a statement of what the will of God is. Was this will of God accomplished in Thessalonica? It seems it was not in Corinth.