Paul's Interactions With Jews And Greeks In Acts

Most Christians or "Christians" one is likely to meet in the West (or likely anywhere) are pathetic thinkers who do not know the necessary truths of reason, or the actual doctrines of the Bible, or the scientific paradigms of their day very well.  Historical evidences are foreign to their commitment to Christianity, but they might confuse the concept of historical evidence for logical proof even if they were to contemplate the former at all.  Ask even the most basic or obvious philosophical questions, like whether anything is true in itself (logical axioms), what verses in the Bible affirm or suggest certain ideas, what probabilistic evidence there is for Christianity, or its relationship with necessary truths and scientific models, and silence or some asinine answer is more likely than not to be their response.

This is not how the apostle Paul is presented.  Acts 17:2-3, 16-17, and 18:4 mention that Paul reasoned with his Jewish and Greek audiences about Jesus being the Messiah and elements of more general Christian theism, such as in his address on the altar to the unknown god (17:22-34) in Athens.  Later, in Ephesus, Paul continues his articulation of philosophical arguments (Acts 19:8).  Apollos, a Jewish man from Alexandria who is aided by Priscilla and her husband Aquila, does similarly in Acts 18:27-28.  He is said to have vigorously refuted other Jews in public debates by showing that the Old Testament—when the text says Scriptures here, it needs to be remembered that the Old Testament was what people at the time had access to in written form—supports Jesus being the Messiah.

In order to be true, words in some of these verses like "proving" would need to have the lesser, more colloquial meaning of "provide evidence for" rather than "logically prove something is true by necessity," for a great deal of Christian metaphysics is logically possible but unprovable despite how some aspects have evidence for them.  One could show it follows/is true by necessity that Jesus is the Messiah if alleged eyewitness reports about him are true and if things are as they appear.  It is impossible to prove many things, some of them as basic as whether the past existed more than a moment ago, yet one can prove that they are probable in light of evidences.

Regardless, Paul and Apollos are at a minimum said to be actively trying to give philosophical evidence for their Christian stances.  Christianity is, after all, nothing more than Judaism with some additional components, so the Old Testament would have to be be both consistent with and favorable towards the figure of Christ and his teachings for the latter to be correct, since Jesus affirms the former (Matthew 5:17-19, 15:1-20).  The book of Acts does not clarify in these passages what exactly Paul and Apollos said to their Jewish or (in Paul's case) Greek interlocutors, but it does say talk about Christianity as if it is true and mentions Christians talking as if the evidence really is on their side.

There are philosophical matters far more foundational, penetrating, and weighty than whether Jesus is the Messiah, as important an issue as it it.  Logical axioms, the existence of an uncaused cause, whether this being has a moral nature, what the precise obligations of justice are if there is such a thing, and so on are far more important than cosmic redemption.  Nothing is true apart from logical possibility and without logical axioms as a prerequisite (these things cannot be any other way and are absolutely certain); justice is more important than mercy because the latter could only be non-obligatory and requires the former.  Things like various events of human history and the status of Jesus cannot be proven, but there is evidence for such things, and the protagonists of Acts are not fitheistic.