Although oil sands are abundant, they are one of the dirtiest ways to extract oil from the Earth. They require large amounts of natural gas and fresh water for extraction. Also, the consumption of crude oil from oil sands continues to produce greenhouse gasses which contribute to global warming. This does not make our energy any more safe or secure.
Oil Sands do improve energy security, at least for the moment. In the long run, it will eventually run out and as a result people will be fighting over it. So in the long run, a more reliable and efficient energy source will need to be found or created such as harnessing the suns power in order to stabilize our energy security problem that might arise.