couldnt mix faith and music myself, the music is more important IMO. id find it unlikely that its been a problem because the bands are of a worship nature, maybe they just weren't very accepting, regardless. try to find a good group certainly, and id say keep your options wider than just worship, but dont necessarily rule that out either, as it seems its clearly what you'd prefer to be playing if you had a choice. i didnt realise there was many of that type about in the uk, havent seen any up here (glasgow area) myself. havent been looking though as its not my cuppa. good luck finding something ^ ^
im familiar with some stuff like demon hunter, extol, august burns red, impending doom etc, not technically worship just christian. i actually hadnt heard of Delirious. well that seems unlikely from what you're saying, but i mustn't have known they were a band/praise n worshop specifically. 