You are right that the opposite of materialism is not Christianity. I’ve made the point several times in my posts on this topic, if not this one, that the door is wide open to a nova of beliefs, nova being the term philosopher Charles Taylor calls it. We see that today as materialism or physicalism is losing sway. Many, including physicalists like Carlo Rovelli, are speaking openly of the consonance with eastern philosophy and mysticism. The best of those in my mind is by Austrian physicist Fritjof Capra in his book The Dao of Physics. I have expressed in other posts that my interest, as a lifelong Christian theist, is to attempt to understand how today’s science fits or conflicts with what I call biblical theism. That just happens to be my journey.