I would understand 'modern age' to include possession of the will and the technology necessary to prevent the British from occupying to begin with
I'm not sure why you'd confuse military conquest with an epoch, or even why the British conquest of the sub-continent was profound in a historical sense; India has been conquered before by earlier marauding invaders, British were merely the last. None of the earlier invasions were epoch-making, so I'm not entirely certain why you'd consider British wins in the battles of Plassey, for example, to be qualitatively different from, say, the Battle of Tarain, or even the First Battle of Panipat. Perhaps your euro-centricism is at display here?
As for will, you seem to be under the impression that the British state completely subjugated India as a whole. This certainly wasn't the case; the British East India Company, (and not the British Empire, as you will see) was one of the many players in the Great Game. In addition to a certain monopoly over opium, tea and other exotic stuff, they also offered military solutions, not dissimilar to Blackwater in contemporary times; legions of Indian kingdoms outsourced their military from the British East India Company. Indeed, they continued doing even after the Company was "nationalized" in the wake of the events of 1857; they merely changed their outsourcee from a public-limited company to a governmental wing. This continued till 1947; one of the first resolutions (and some would say the continued crisis in Kashmir) of the United Nations were because of these agreements: now that the British were finally leaving, questions were raised on the validity of these military agreements, going back three hundred years
In short, even using your non-standard definition of "Modern Age" (which, must say, is quite unique), I still don't see how the British brought about the "Modern Age" that you so define.
Was it not poverty, religious beliefs (idol worship), and lack of technology preventing such
Here's a thought, and this might come as a surprise, but you have no idea. None at all. May I suggest reading up a bit first, say, the White Mughals and the The Last Mughal? Among other things, you'll be interested to know that a) the British came and tried to monopolize trade in India because of the region's wealth, that the battles fought by the British were against Muslim republics; the first Battle of Independence in 1857, for example, was widely seen as a jihad even though most of the foot soldiers were Hindu. I'm not sure where idol worship comes into play in this discussion at all, or even why it was a problem militarily speaking.
You have a point on military technology; I mean, it's clear that the armies of the British East India Company were better trained, better equipped and more efficient than the native armies. However, and here's where the _Company_ bit comes in, native rulers typically used a mixture of diplomacy, trade, intrigue _and_ military options in their foreign policy; while they were used to negotiating trade or forming military alliances with kingdoms, they clearly didn't know how to do it with an anonymous public limited _company_. You can't, among other things, defuse its threat by giving your daughter in a matrimonial alliance, for example. There is no hear, no _emotion_ involved in working with a 200 year-old trading company, and the native rulers, for all their might, power, wealth and diplomacy, simply couldn't tame the beast.