In contrast to emphasis on personal salvation and religious patriotism of biblical Christianity, 'second Christianity' concerns itself with common humanity in relation to a divine Presence, and confronts the global problems of our modern world.
Hick has an compelling view of how a variety of religions can be unique expressions of the Infinite Reality. I was particularly interested in his early thinking on this. Note especially chapter IV "Christianity and Other Religions." This book is certainly the precursor to his later seminal works on pluralistic religion. You don't have to agree with everything he says but it's worth the read.