A problem with some books on theology is that they mix positive (this is what exists) and normative (this is what should exist) ideas - this problem was more common in earlier books - like, say, oh ONE FROM THE 19TH CENTURY - but one can still find it abundantly. Ryle was probably twice as intelligent as I'll ever be, so take my opinions with a grain of salt - this feels old-timey, in a way the world has thankfully moved beyond. Contemporary theology books tend to put the sayings of Jesus in the time and tide of context - and the reader is more informed for this happening. This just doesn't happen in Ryle's book, probably likely because the idea of Jesus was supposed to have a timeless feel. Which may be true, but a 21st century reader is 2 centuries removed from Ryle and 2 millennia removed from the life of Christ.
Ryle's take on John has a cognitively objectivist slant to it - this made sense for his time of writing, but not so much today, where it is very possible to have two opposite but strangely both correct interpretations of a parable. Jesus *could* have come out and said what he meant. He, by and large, did not. I can't help but believe Ryle's conclusion was that educated people needed to give the correct interpretation for believers; I think while there's wisdom in this, there's also room for interpretation *by design*.
A classic example: Ryle speaks of John 14:6, "I am the way, the truth and the life", etc. (I forgot in which volume he does this) about how this is clearly saying that salvation must come through belief in Christ. Jesus could have been talking just about, you know, death and dying. An obvious flaw in Ryle's line of reasoning is that it's hard to conceive of a just God dooming a Mongolian herder born in 50 BCE to never be able to achieve salvation because of an accident of birth.
Ryle takes a stance on the historicity of the Gospels in a way that feels anachronistic. His claim that Jesus performed miracles, and this is certain because no one in the Gospels argues against Jesus performing miracles, feels like circular reasoning to me.
Ryle spends a lot of time explaining the need for suffering. I don't know - feels hollow. The problem of pain and the injustice of pain has been one that has plagued all religions since the very beginning, and while I think Ryle believed he found the answer it didn't help me much. Sometimes suffering yields a better human being. Sometimes - as in a child with cancer, a PTSD sufferer who medicates through drugs and alcohol, or someone with brain damage - it doesn't, at all.