I have just glimpsed a small part of what happened to me all those years ago when I gave my life to Christ. Why did it take some time to feel as though it was real, and not just a trick? I'm not stupid, but the mind I have regarded as "clever" was in fact very stupid in some ways.
When I gave my life to Jesus, He made me a new creation. As part of this, I now have two minds - my natural mind and my spiritual mind. Allowing for my stroke, my natural is still pretty good at understanding some things, but as you can see from the fact that it's taken over 50 years to realise this, not only are there many natural things I don't fully appreciate - there are many things for the spiritual mind to grasp.
When I became a follower of Jesus, for some time I didn't realise that my natural mind and my spiritual mind were engaged in a fierce warfare. Jesus never let go, even though my mind was relatively strong. I can't express strongly enough my amazement at the glory and faithfulness Jesus has shown and continues to show.
I expect non-Christians to wonder what I'm talking about, but what really concerns me is how many Christians will not identify with this. If you don't fully understand this, please don't discard it. Keep searching - God will work through it with you including bringing the reality of verses to you.