We shouldn't be so quick to assume that we understand anything about God. I feel like some people cling to the Bible because they don't really think God exists... at least, not beyond a book. A book is something easy to believe in; it's firm, touchable, readable, etc. But God -- God is complicated, invisible, practically undetectable for the average man or woman, in the same way that oxygen and nutrients pass through our body without our conscious knowledge. Who can really believe in something that they haven't seen themselves?
God's realm is the heart and it is through a person's actions that we can determine their closeness to God. Selfless and loving people are better acquainted with the Spirit of God than those who point fingers and judge; no matter what a person professes with their mouth, it is by action that we are saved, by action that we come to know Christ, and essentially it is by actions that we are judged.
Look to a person's actions, and you will see the true quality of their faith.
By their fruit you will recognize them. Do people pick grapes from thornbushes, or figs from thistles? Likewise every good tree bears good fruit, but a bad tree bears bad fruit. A good tree cannot bear bad fruit, and a bad tree cannot bear good fruit.