What is the one catchall category of responses that unbelievers give when responding to hearing the Word of God? Unbelief.
That’s right. Everything they say is grounded in their unbelief.
Why is this important to know? So your answers address their unbelief not their presuppositions.
In other words unbelievers are speaking as souls dead in sin not as rational creatures with the ability to reason.
For instance you could respond to the cry for evidence like this: Sir, the reason you are seeking evidence is that you are dead in your sins. Did you know that?
Or “Sir, you seek evidence because you have not the Spirit of God. The things of God are known by the Spirit of God. Did you know that?”
Therefore our primary injunction to them is to cry out to Lord for salvation. They’ll never receive nor understand our answers to their questions until they receive the Spirit. Until they are saved.