Christianity is big. Christianity is a great culture. That is good, as non-Christian Tom Holland documents in his book Dominion, but that is Grand Christianity, not mere. Jesus told his disciples that they would not be like the world. They would be servants. They would be like children. To comply with that, this book is the writing of one mere Christian.
Similarly, science is big. Science is a great culture. That is good, but Grand Science lacks an anchor in morality. Science can be misused to support great evils. That has happened, and it will happen. This book has only a beginning of the study of that problem.
It may be obvious that the term mere comes from C. S. Lewis, author of Mere Christianity. This book does not disagree with Lewis, but it is a very different book, using mere in a more humble way.