It's usually possible for people with even the most orthodox beliefs to be devout but unobservant (and vice versa). If "being religious" requires liturgies and service for you, then obviously their observance, but otherwise it probably isn't. In the latter case, finding a good church invariably aids and edifies ones religion, but is not strictly necessary. I would say that belief in a deity or deities and at least SOME doctrinal tenets on the subject are required, except that many people attend (or even lead) religious services despite little or no beliefs about any deity. In those cases liturgical forms are usually necessary, yet belief in a deity is not only optional, but sometimes an active impediment.

So tell me what you mean by "religion" and I can give you a better answer; I don't really like the term because it carries connotations of orthodoxy as an end in itself, of rules and practices that stifle the investigation that begin and develop ones relationship with God. I like to think I have a very strong AND unobservant faith; the last time I was in a church was when touring the local cathedral with my wife and friends after my wedding, but I'm absolutely certain of my faith in Christ as Lord and Savior. I try to be receptive and attentive to the many ways God speaks to us on the many points where existing scripture, doctrine and prayer are either inconclusive or wholly silent, but uncompromising on the comparatively few points where God is uncompromising. Thus for me "being religious" in the largest sense means a life demonstrating a sincere faith in God to the best of ones ability, with His aid through Grace, knowing we all sometimes err. Many who consider themselves very religious condemn my insistence on the Trinity as outmoded and exclusionary; as many more condemn my non-observance of ceremony just as strongly. "Religious" means something very different to me than it does to them, which is why I prefer to say I have faith rather than religion. My doctrine is little more than the Nicene Creed, my dogma little more than "in necessary things unity; in uncertain things freedom; in everything compassion". Beyond that, consideration of scripture, teaching, prayer and meditation can be instructive, insightful and faith affirming, but we must be careful to remember mans capacity to err in sincerity, and not overcommit to or demand belief in things which are likely and perhaps even true, but not vital, while always recognizing non-negotiable things as just that. That's probably not a bad rule for any religious belief, but I find it works quite well for Christianity.