Complex sentence: It was the Bible that shaped, especially, Protestant nations, but its influence is now rapidly declining and there are fewer and fewer people who are familiar with its stories, values and its message and who live according to its wisdom.
Split into simpler sentences: It was the Bible that shaped, especially, Protestant nations, but its influence is now rapidly declining. There are fewer and fewer people who are familiar with its stories, values and its message and who live according to its wisdom.