1 Thessalonians 4:3

For this is the will of God, your sanctification: that you should abstain from sexual immorality;

Surrounding context

4:2 for you know what commandments we gave you through the Lord Jesus.

4:3 For this is the will of God, your sanctification: that you should abstain from sexual immorality;

4:4 that each of you should know how to possess his own vessel in sanctification and honor,