Plato's Cave Allegory - How to respond to the argument in favor of ignorance?

I have a friend who is unfamiliar with both philosophy and Christianity. I thought I would to share the Christian truth by starting with the Greek philosophical concept from Plato known as the "allegory of the cave," and then from there, lead them into the concept of prophecies (i.e. that came true of Jesus). I felt that the cave allegory was very useful for opening up discussion because it helps to establish two very key fundamental things: 1) our reality the way it is presented may not be (and is not necessarily) true (e.g. the world teaches we evolved from nothing ultimately, but the truth is that God created us), and therefore 2) there is a serious need for us to seek the truth, not only despite the push-back from the world, but also so that we can share the truth with our friends for their own sakes. So I started with Plato's cave allegory, and I explained it and said we should seek freedom from this world and seek the truth, even if we may be rejected by the world (our friends)... Very basic foundation to start with, I thought, before just jumping into the OT prophecies of Jesus... However, after some discussion, he said > "Freedom? Tell me what was his [the cave man who escaped] freedom? The > world (his friends) won't accept the cave man. When he was in the cave > he knew a little and that little is what gave him happiness!" My friend's argument that followed this was that we should not seek the truth but be content with being ignorant, because that's when we have some happiness, and we aren't rejected by our friends. How can his argument be countered? Or how can the general trajectory I went for be improved? I suppose it is possible to skip the cave allegory. But if my friend is content with believing what he is taught and would rather care about the little happiness he has "in the cave", then how could he even begin to accept that maybe there is something more?