Warren Wiersbe makes an excellent point that…

We must keep in mind that the pagan religions of Paul’s day said little or nothing about personal morality. A worshiper could bow before an idol, put his offering on the altar, and go back to live the same old life of sin. What a person believed had no direct relationship with how he behaved, and no one would condemn a person for his behavior. But the Christian faith brought a whole new concept into pagan society:

What we believe
has a very definite connection
with how we behave!

After all, faith in Christ means being united to Christ; and if we share His life, we must follow His example. He cannot live in us by His Spirit and permit us to live in sin (cp 1Jn 3:7, 8, 9 where “cannot sin” = cannot sin as a lifestyle). (Wiersbe, W: Bible Exposition Commentary. 1989. Victor)