This point has been discussed even in Pope Francis' The Joy of the Gospel. I've been carrying it around and rarely daring to articulate it for years.
Back in about 2005 a priest, who I will not name without sizeable bribes, made the same point to me. He said it a different way. I will paraphrase because I don't remember exactly how he said it.
What he said amounted to it does no good to tell anyone about the spiritual life until they have had an encounter with Jesus and really have come under the control of the Holy Spirit. Until there is a significant conversion experience the only thing you can do is tell them Bible Stories and keep hammering them with the Gospel until they "get it."
Until they are under the control of the Holy Spirit, so the Holy Spirit can enlighten them of spiritual things, it does no good to try to make them understand anything. They are still carnal and until they become spiritual they will not "get it."