“This seems to be what Jesus is talking about when he speaks about casting our pearls before swine. It’s certainly what he did with the Pharisees, when he reached a point where he insisted they would get no further signs from him nor would he even bother answering their questions anymore.”
(Stephen Kneal) It is not uncommon, nor unreasonable, for people to ask us for evidence of why we believe in Jesus. It is perfectly right and proper to give people a reason for the hope that is in us. Indeed, not only reasonable, but something the Bible demands. God condescends to reason with us (cf. Isaiah 1:18) and calls us to reason with others (cf. 1 Peter 3:15). It is good, right and proper to offer genuine reasons to believe.
But as a soteriologically reformed believer, I am well aware that unless God moves in grace towards people, they cannot and will not believe. If Total Depravity tells us anything it is that we do not by nature reach out to God. Even if you’re not reformed, it’s pretty hard to ignore the plain statement of Romans 3:9-18. And then there are the words of Jesus in John 6:44. There are other verses saying much the same thing. Unless God moves in grace towards us, we aren’t going to seek after him and we can’t come to the Father.