See, I don't believe that unless you are talking about infiltrating them with prayer. As a Christian, I believe everyone should know the Light and while it is our mission to try and bring the Light to those living in the dark, we can only do so much.
Johnson tried to tell Adamson about the Light but Adamson didn't want to listen and doesn't want to be bothered by Johnson or his Light. The only thing left for Johnson to do is pray that his Light will eventually lift Adamson out of the darkness.
If Johnson keeps opening up Adamson's door to talk with him, this is going to cause Adamson to be more and more upset and cause him to him to draw further and further into the darkness.
Thank you for your input. Reaching Adamson will indeed take a lot of praying. I think the dark room can be infiltrated, but very subtly and carefully. It would be, possibly, not even talking to Adamson. Maybe just going into the room and moving about with your own brighter candle, being friendly, joyful, etc. - Definately not pushy or antagonistic.