The first way by which Satan tried to reduce the church’s growth was by attempting to infiltrate the group. He used a slave girl who was a fortune-teller and under the control of one of his demons. The girl accurately described Paul and his friends: they were the servants of the Most High God who were proclaiming the way of salvation. Of course, it has to be remembered that belief in a supreme being and in a method of salvation was not unique to Christianity. No doubt the possessed girl was well-known in Philippi and when the citizens saw her with the men they would assume that Paul and his team were connected to her temple and ignore their message.
This kind of strategy by the devil is common. Today, he wants to create the impression that all religions are the same and he can even use biblical terms as his slogans. Not every attempt at unity originates in heaven; some of them have their roots in the enemy of our souls.
The second way by which he attempted to stifle the growth of the church was by stirring up opposition that resulted in imprisonment. This took place when the owners of the slave girl lost their means of income. They instigated the local civil authorities to arrest the men on a trumped-up charge of being anti-Roman, which would be a very effective accusation in Philippi because it was a Roman colony. The result was that the leaders (Paul and Silas) were beaten and arrested.
From a human point of view it would have been expected that the imprisonment would curtail the growth of the new movement. Yet in both these attempts, the devil defeated himself. In the first instance, the girl was delivered from her demonic possession, and in the second the jailor and his family were converted. This is a reminder that the Lord is able to overrule the intentions of the devil and bring about growth in the church.