I gave you free will, so use it exactly as I command you to!
Of course I have free will, I have no choice.
I have always thought that the topic of free will was very interesting as it applies to religious thought and the properties of supernatural beings. If we are to accept that the Christian deity is a god in the truest sense of the word, then we must concede that it has a particular set of very important properties, chief among them being the all-knowing property of omniscience and the all-powerful property of omnipotence. Without these properties, it would seem that God would be reduced to merely a very powerful being. An omniscient being would necessarily know every intricate detail of every event that has ever happened, is happening, and that will happen. In short, an omniscient deity knows everything by definition. If this deity is also responsible for the creation of all reality, then it follows that every action and thought that Adam and Eve had was predetermined before the universe even existed. God created them knowing that they would both disobey him, become exiled from Eden, and then be subsequently doomed to a life of difficult labor, suffering, and ultimately death. He also did this knowing that every single one of their progeny would suffer the same fate, despite not being directly involved. Their decision to disobey was known to the omniscient creator before the universe existed, then, exercising the power of omnipotence, he created the universe anyway.
How can free will exist if there is prior knowledge of every action, thought, and decision that a supposedly free-willed individual makes? And then, a deity armed with that knowledge, creates a universe whose events play out in the exact sequence that is already known to him? Does this not imply that the "choice" to disobey was merely an illusion, and this action was preordained before existence? It seems to me that there exists a contradiction between free will and the godly property of omniscience, suggesting that they are mutually exclusive ideas. If a god is truly omniscient, free will is an illusion, and all of our actions and thoughts are purely deterministic. On the other hand, if we actually have free will, then we are necessarily non-deterministic, God is not omniscient, and arguably not a god.
With all this in mind and despite having been born in an area with a higher than average belief in the supernatural, whose adherents maintain that an essential property of humanity is individual free will, I have never heard an argument that satisfactorily remedies this inconsistency. Then again, if the metric by which we measured the validity of a religion was internal consistency, all human societies would be atheistic. This is obviously not the case, so inconsistency must not be a terribly important factor in determining where one’s religious loyalties lie. Of course, this set of conclusions is only my opinion and may be erroneous if I have made inaccurate assumptions about free will and properties of supernatural beings. My argument for the mutual exclusivity of free will and omniscience could be rendered moot by considering that the creation of all reality also included the creation of an arrow of time. In that case, arguing for causal consistency with respect to predetermined events is meaningless. I suspect that taking such a metaphysical stance about attempts to systematically examine supernatural claims precludes any dialogue on the subject, though, so I will reject that so I can keep blaspheming. Perhaps god-like properties need to be revised, with certain caveats added to resolve the inherent conflict between fundamental ideas pertaining to humanity and the divine.
Considering the subject of free will more generally, I am assuming that either free will exists, or it does not. Turning to the absence of a 'doctrine of free will' in the Bible and keeping the previous proposition in mind, I would have to say that the doctrine of free will in the Bible is implicit, that is, it is implied by the fact that the deity of the Christian faith bothered to have compiled a piece of literature that lays out the rules or codes of conduct for his myriad of subjects to follow. In my opinion, it would be unreasonable and pointless to demand or even suggest specifically or generally codes of conduct to humans, if these same humans were absolutely deterministic and had zero input as to how their bodies and minds would behave. Every command given by any god during any time concerning any human behavior implicitly assumes that the subject has the ability to choose to follow this commandment, or to not follow it.
I do wonder if there could possibly exist a gradient of free will, that is, some things that we can freely control about ourselves, or at least appear to, and some things that we cannot. It seems fairly easy to accept and assume the existence of free will concerning higher level thought processes, but what about more basic mechanical and instinctual functions? Do we have the free will to prevent the next rhythmic contraction of cardiac muscle that sustains our lives or is it mediated by completely deterministic electrochemical processes? Do we have the free will to prevent an instinctual lustful desire when presented with an erotic image or is it an inherited trait that engendered a higher degree of reproductive success over our evolutionary history? Do we have the free will to adjust our perception of the passage of time or is that rate just a fundamental property of the way human brains are structured? Do we have the free will to purge specific memories that may be harmful to our day-to-day functioning or is this archiving a passive property in which we have no control over? To me, some of these questions seem to blur the line between our assumed free will and being at the mercy of purely deterministic processes. This is especially so if the same applies to the previously mentioned higher level decision making processes. Maybe these processes are only ‘partially deterministic’ in that the potential decision events perceived by the mind are massively constrained by external parameters, and what we ultimately decide from is only a small subset of potential decision trees. I know I kind of went off on a tangent there but to answer the question directly about the doctrine of free will in the Bible, I would say that this doctrine is not necessarily in the Bible, but it is the Bible.