A Christian, in the true sense, believes the Bible is the word of God. There are liberal thinkers who hold to a form of godliness although they have denied God's power. They believe the Bible contains the word of God. Much like atheists and agnostics, liberals try to explain away miracles and prophecy because they lack faith and imagination.
I read a profile on Isaiah in Reader’s Digest that was written by some very liberal thinkers. Isaiah prophesied from 740-680 BC.
Isaiah 7:14 says, “Therefore the Lord Himself will give you a sign: Behold a virgin will be with child and bear a son, and she will call His name Immanuel.” The word they bring into question is “virgin.” The King James, Douay, NAS, & NIV Bibles all translate it so. The Revised Standard Version, used by Reader’s Digest, translates it as “young woman.” Reader’s Digest fails to mention that the RSV footnotes show the alternate translation as “virgin.” They “speculate” that this unnamed young woman could have been Isaiah's wife and that Immanuel could have been his second son. Pure conjecture in an attempt to refute the virgin birth. A denial of miracles and prophecy.
They also contend that the book of Isaiah was heavily edited in the centuries following his death. Until recently, the oldest Hebrew copy of the book of Isaiah was completed about 900 AD. With the discovery of the Dead Sea scrolls, a copy of Isaiah was found which was dated to 100 BC. A thousand years older and the differences were considered negligible. That’s a testament to the scribes and translators who, through their painstaking devotion to detail, have given us a modern Bible virtually unaltered from the ancient manuscripts.
Reader's Digest also argues that the last 27 chapters in the book of Isaiah weren’t even written by the prophet but by one or two of his disciples in the post exilic period, that is after the Babylonian captivity. It should be noted that Christ and his apostles made no distinction. They quoted passages from the first 39 chapters and the last 27 chapters indiscriminately as the words of Isaiah the prophet.