Did Paul's converts in every city he ministered in face persecution right away?
Yes. Paul’s converts, not only in Galatia but also in Philippi, Thessalonica, Berea, Athens, Corinth, and Rome—any place Paul ministered and gained converts out of paganism—immediately came under the pressure of persecution. They had just recently been saved out of that background, yet they died for their faith rather than returning to paganism.
Les explains that Paul’s converts did not face this only in Galatia, but also in Philippi, Thessalonica, Berea, Athens, Corinth, and Rome—any place Paul ministered and had converts out of paganism. As new believers just recently saved out of all that background, they immediately came under the pressure of persecution. They did not go back into their paganism, though Les says it would have been awful easy to do; they died for their faith. He contrasts this with Christianity today, asking how many professing Christians would stay with it if heavy persecution fell and they had to give up their lives. Les also notes this was the main reason Paul did not really encourage marriage: it is easier to die for your faith if you are single than if you have a loved one to worry about.