schmunk
Why oh why oh why?
You may be interested in this Spectator article about HTB & Alpha. It may change your outlook.
https://life.spectator.co.uk/articles/alpha-rising/
I'd never heard of Holy Trinity Brompton, but I can remember the Alpha Course being pushed on me when I was at University. The reps 'tricked' me and several friends into attending multiple little 'suppers' which culminated in joining a larger group for an unannounced Christian talk. After this, they kept going with friendly-but-snide techniques to try to drag me in.
I would personally liken it to a cult.