On most dating sites, you can use a variety of filters when you search for other members you might be interested in. The filters can be just about anything: height, gender, body size, religion, hobbies, and more. Because of this, many people believe that regardless of their preferences, joining a general dating site is the first step. This is true to an extent, but given that there are plenty of niche dating sites, you should definitely give them a look as well.
What separates niche dating sites from people on general sites is that the people on are more adament about their preferences. Therefore, if you feel strongly about only dating someone in a particular category, you're better off joining a niche site. On a general dating site, you may also receive a lot of interest from people who don't fit your criteria. On a niche site, however, you have the advantage of knowing that anyone who reaches out to you will already fit into a certain category.
Among niche dating sites, Christian dating is one of the largest categories. Within this category, Christian Mingle has the greatest number of members, in part because they have been all over the airwaves in terms of commercials.
The site asks more religion-centered questions in the profile section, and it therefore makes sense for people who place a special importance on religion to use this site instead of a larger site such as Match.com.
On the other hand, if you want to use a matchmaking service that uses psychological research to find you the ideal match, you only have one real choice, eHarmony. There are not enough niche dating sites that also own a powerful matching algorithm. But the good news is, when you join eHarmony, you can be really specific about what you want. So even though it's not a niche dating site, your matches should be the type of people you are looking for anyway. I highly recommend that you get this eharmony free trial offer if you want to try out the site.
The reason I say that is because eHarmony is a very different kind of dating site, and you have to use it to really understand how it works. Regardless of the niche you are interested in, it's worth the time to give eHarmony a trial.