Well apparently he wasn't much of an evangelist. He preached for weeks at a time and you're making the contention that not one person out of a whole city became a Christian? Or are you saying that everytime Paul baptized one he told them about a secret Sunday service (unmentioned in scripture) and that the the new Christians went alone to unmentioned Sunday services while Paul continued preaching on the sabbath?
Try reading it again.
I merely pointed out that the phrase "nearly the whole city" does not mean "the church", so whatever Luke was descrining is not a church worship service, but rather an evangelistic service of sorts. Some gentiles came to Christ and were baptized after this all happened. See verse 48.