There are some who are born into already observant families. Colloquially they are called "FFB" or Frum From Birth. Then there are those who are born into families who have not been involved in Torah observance. Some call them "FAB" (perhaps short for FABULOUS!) or Frum After Birth.
There are a host of different segments of Judaism available today that fit within these two main headings. One can find Litvish Jews, Ashkenazi Jews, Sefardi Jews, Modern Orthodox, Ultra-Modern Orthodox (I'm even convinced there must be an Ultra-Ultra Orthodox Jew somewhere too!), Reform and Conservative. There are secular Jews too. In fact, there are so many classes today, that we can become rather lost in understanding any particular category altogether! If one is looking to find a marriage partner on the main Jewish dating sites on the Internet one finds oneself with the difficult task of categorising oneself into one of these categories. It can be frightening experience for anyone lacking a proper understanding of just exactly what it means to be one of "those" Jews!
From the beginnings of the Jewish people there really was only one type of Jew. An Abraham Jew! And he had a son. One could call him an Isaac Jew! And after him came Jacob. Perhaps one could call him a Jacob Jew! Jacob had 12 sons, and while each may have had a different name, they were all known as the sons of Israel. (Jacob's name was changed during a battle with an angel. He became known as Israel from that point onwards.)
From the 12 tribes of the Jewish people came about 70 souls who descended into Egypt. And from these souls came the 600 000 root souls of the Jewish people who remained in Egypt until their liberation through Moses - the servant of G-d, who by the command of G-d, took the Bnei Yisrael - the Children of Israel - out of Egypt, to bring them into the land of ISRAEL. The Children of Israel were taken into the land with that very same name as it is today.
In truth, there is only one Jew today - he/she is a child of Israel. We can classify each other into as many categories as we wish to. At the end of the day however, we are all the same. There is nothing to differentiate us. As the Alter Rebbe states clearly in Tanya - we all have one Father. We all come from the same place above. And while it may appear in this lower world as if we are different - some wise, some simple, some who are Tzaddikim and others who are not... in truth, every Jew is considered a child to G-d without differentiation.
But still, we have the Jew who was fortunate enough to have been brought up in a Jewish home from birth. And we have the Jew who did not have this good fortune. As the Rambam discusses, this Jew is known by the name of "Tinok Shenishba LeVein HaGoyim" - A child who was held captive amongst the nations of the world. Just as a prisoner is forced into situations beyond his control, very often being totally unable to remove himself from events happening - and being completely influenced by the surroundings he has been placed in, so too is this Jew forced - against his truest wishes - to live a lifestyle totally foreign to the Jewish soul!
Yet, be that as it may, he is no less a Jew than the greatest Tzaddik in the world. He too is a Jew and there is no difference between him and others. The Rambam says that we must be very sensitive to this Jew for, having been held captive amongst forces against the true wishes of his soul, he has been forced to live a life against his real will. In fact, he too wishes to serve G-d as much as the greatest Tzaddik... just that he may be asleep, not completely aware of what Torah and Mitzvos are all about.
Therefore, the Rambam says that it is fitting to return them in repentance and to draw them in peaceful ways - back to Torah and Yiddishkeit - until they return to the strength of Torah. The Rambam concludes - one should not be in a hurry to kill them!
One wonders at the Rambam's stong language. Yet, how many Jews trying to find their ways back to Torah will be looked down upon by "those already there"? How easy it is for one "already there" to feel nothing of one who is not connected to Judaism (apparently!)
Our job is not to criticise another Jew for his lack of observance. Certainly there are times to rebuke another - but one must be knowledgable in the laws before attempting to throw one's weight around! Our job is to be there for another. Not to insult, not to hurt, not to walk away in disgust - perhaps the Rambam is correct - not to kill another, for aren't all these things exactly the same?!
The Rebbe in the video below speaks about what a Jew really is and the necessary outlook we have to have towards another - who is apparently lost - sleeping! As the Rebbe has said before, if you see another Jew not yet leading an observant life, do not think he is any less greater than you are. Perhaps he is just asleep! We cannot know the greatness of another until we wake him up. Once we wake a person up, all his soul powers and faculties can be seen clearly. It may well be that when another is asleep that he may seem to be worthless, unintelligent and a lost case. But when we awaken them, it may well be that we find, that not only are their faculties and soul powers great, but we may find that in fact, they are even greater than ours are.
Our job is to see this greatness even in the deepest sleeper. Our job is to wake them up. To make them aware of the Jewish soul which they possess, and her powers. Our job is to realise that just like we are children of Israel - so too are they.