With all due respect to the late Dr. Scott, Martin Luther, and others, I disagree about the book of James not belonging in the Bible. It contains important guidelines about living out the Christian life.
Experiencing God's salvation by faith has always been a fundamental teaching of the Bible, including the OT. If you believed what God said about something, and took whatever action was appropriate based on that belief (obedience), then you received the corresponding benefits. If you didn't believe, then of course, you didn't act in line with what God said, and you didn't benefit. In the NT, the fundamental teaching is that Jesus of Narareth is the Christ/Son of God/Son of Man/ Son of David/King/suffering servant of Isaiah 53 based on eyewitness testimonies of how the teachings of Jesus, how he lived his life, his death and resurrection matched those prophecies. To believe this testimony is essential because it is believing what God has said (the NT claim about Jesus), but it doesn't really stop there. As such, he is Lord and Master, and his word is supreme, so professing believers should make the attempt to live according to his teachings. So when he talks of loving and not sinning, to accept that teaching is all part of the believing (this also extends to the teachings of the Apostles, because he said, "whoever listens to you [the Apostles] listens to me.") It makes sense, doesn't it? If I believe that smoking is bad for me and will kill me, assuming I want to live, I'm at least going to try to quit, aren't I? In the Synoptic Gospels, believing Jesus to be the Messiah sent by God meant obeying his teachings; that was the expectation for people living at that time. After the crucifixion, resurrection, and ascension of Jesus, and Pentecost, the gift of the Holy Spirit and inclusion into the promise to Abraham comes into play, but how people were to live was never negated.
We need guidelines to live by because, even though our inner self is regenerated, the outward self, including how we think, should ideally be brought into conformity with the inner self. Although this cannot be fully achieved, we should be on the path to becoming a fully integrated being. Loving God (and his Son) is first and foremost, and making the effort to please God with our lives is part of loving God. It's part of praise, worship, and thanksgiving. It's a natural consequence, isn't it? When you have legalism, the love has been lost; it's all about self--"What do I get out of it?"
Yes, the canon does consist of different perspectives from different authors, but I see that as a good thing. Each has something to contribute to the big picture, and it somehow all fits together.