He makes some good points in there, including his warning to Christians not to accept cultural definitions of things (sex, for example) just because we think we have to accept them to be part of the cultural conversation about them.
But I think the whole premise of Christians regaining their cultural influence is mistaken. It did seem like we had cultural influence for a while. Then it seemed like we lost it really fast. I mean, really fast. So fast that it seemed like any influence we did have was just an illusion.
And I think that is, in fact, the case. We never really had any influence over the secular culture. We fooled ourselves into thinking we did, because Christian culture and secular culture moved in parallel for a while. But as time went on, Christian culture became more like secular culture, not the other way around.
The most important thing to do is, as Forster says, “Recover the idea that Christianity is a distinct way of life.” It’s hard to change the course of a culture be being exactly the same as it already is.