One way of looking at dreams - not necessarily the most accurate way though - is that they are partial manifestations or pre-manifestations.

Thought, when thought on for some time, manifests into Thought-Form and then, when thought on some more, manifests into Physical Reality.

So we get...

Thought --> CONDENSES INTO --> Thought-Form --> CONDENSES INTO --> Physical Reality

Using this paradigm, your dreams would fall into the area known as Thought-Form.

At this stage, it's just an indication of what may manifest if you continue your current line of thinking. And since many people do not change their line of thinking in response to a dream, it can seem like the dream is predicting the future when all it is really doing is suggesting a probable outcome based upon your current vibrational offering to the Universe.

I tend to think of it like a train running on railroad tracks.

The thought-form of the dream is the track you are currently running your own train of life on. And if you carry travelling down this track, you will eventually reach the station that the track is leading towards. (The physical manifestation)

But you can, in response to your dreams, alter your vibration and thereby choose a different track to move your train onto.

So, if you are having dreams that make you feel good, you are going to enjoy visiting those stations the track is leading towards, so all is well. But if you are having dreams that make you feel bad, it's time to switch tracks :)

So, are you seeing the future in your dreams?

I would say you are seeing a probable future...a probable railroad track.

But there is no fate. Everything in your universe is under your complete control and you can change your future anytime you wish through the application of some deliberate thought.