The Screwtape Letters

Lewis makes the argument that the Devil's work is never truly over, they can always find something to use against us to make us reject God as he intends. He focuses on a lot of different aspects but relationships tend to be one. He notes how humans interact can lead to conflict and this conflict is what the Devil exploits. Thus it seems Lewis is directing us towards not a worldly ideal human relationship but towards what the Bible views as the ideal relationship between people.

There are also some great ideas such as selfishness of time and unselfishness differing between the genders.

I will likely revisit this.