There are allegories in the Bible, but we must not allegorize sections without biblical warrant. Because God is the Lord of history, he can even use real historical events as allegories for spiritual truths, as in Galatians 4:21-31. Just as exegesis informs systematic theology, so systematic theology informs exegesis because of the first rule of hermeneutics. Creeds and confessions are important, but the Bible is the ultimate authority, not creeds or confessions.
http://www.whatdoesthewordsay.org/uncategorized/46-allegories-sy…-bible-part-viii/