This is the first characteristic of Babylon. Harlot is an outdated word for prostitute, a woman who has sex for money; but sometimes the Bible uses this word figuratively to describe spiritual harlotry, which is the abandoning of our first love, a pure, genuine faith, and faithfulness to God.

The Early Church was born pure and remained pure for as long as it was persecuted by Roman emperors.

But the devil changed his strategy when he saw that the more he persecuted and killed Christians, the more they grew in numbers and in faith. He then simulated the false conversion of the emperor Constantine,  and Christianity became the official religion throughout the territories dominated by Rome. From the moment on, the Church plunged into the Dark Ages. It did not follow the Gospel proclaimed by the Lord Jesus and His apostles and turned into a cruel and profane religious system.