Droopystop,
If you're in UK remember that the 2 largest employers are CHC/Scotia and Bristow, which I believe are both unionised companies where BALPA negotiates pay and conditions of service.
Then look on this forum at the threads on CHC and Bristow redundancies and North Sea pay.
These should enable you to answer your question:
Is BALPA going to help secure job security and a long term future?
It's also worth asking anybody you know who is a junior or mid-seniority pilot with Bristow what they think about what's happening with their pension scheme now, and if BALPA has any influence in that regard.
In most brances of aviation your job security and long term future are only guaranteed for the period of notice stipulated in your contract of employment.
Maybe I'm just an old cynic