I was born to an 18 year old mother and father who are Christian. They put me up for adoption: My (adoptive) father is Jewish and my (adoptive) mother is Christian. Personally, I am Jewish. Regardless of whether or not I have Jewish blood. Now, why is it that if a person's mother is Jewish, that child is automatically Jewish? ...But my neighbor (who was born to Jewish parents) is Jewish only by title. He is not practicing, or hardly practicing (while) I am a practicing Jew...
You're absolutely correct: just being born Jewish is no guarantee of inner goodness or righteousness. There are countless non-Jews whose lives are wonderful examples of kindness and loyalty to God as there are, unfortunately, many Jews who fall seriously short of God's standards. In fact, the Torah teaches that there's no need for a non-Jew to convert to Judaism to achieve greatness in God's eyes...he can grow to dizzying heights within his own world. For more, you might like to see a comprehensive web site on this subject.
But does that mean that Jewishness is something that can be applied and removed at will just like a pair of shoes? If a person's many good acts and elevated sense of morality are what creates his Jewishness, then what would happen if he were to change his mind about it in ten years and choose paganism instead? Would he somehow cease to be Jewish? Could a person be Jewish one week, obligated in all the mitzvos, and legitimately eat non-kosher food the next?
So what's the difference between a Jew and a non-Jew? Judaism, in the Orthodox view, isn't the product of changing communal standards of morality or of personal preference, but the will of God as revealed at Mt. Sinai. We believe it was at that revelation (and through the course of the subsequent 40 years) that God revealed all the commandments of the Torah to the children of Jacob (The Pentateuch and the oral Torah - the core of which is now found in the Talmud - are, we believe, the accurate record of that revelation). There was a covenant and oath taken by the Jewish nation at that time obligating themselves to observe all the mitzvos (see Ex. Chapter 24).
In more general terms, Orthodox Judaism (as I'm sure you already know) believes that conversion consists of three elements: circumcision (for men), immersion in a mikvah and unreserved acceptance of all of the Torah's commandments. This third requirement causes a conversion court the greatest difficulty, as its members must judge a candidate's sincerity, knowledge and most fundamental psychological motivations. Yet the validity of the conversion rests entirely on this acceptance.
It's for this reason, for instance, that you won't find easy access to responsible Orthodox conversion courts on the Internet. No one wants to become a "clearing house" for conversions because that would compromise the vitally important personal contact necessary to judge a candidate's sincerity.
There are, however, organizations and individuals who, for many reasons, feel it their mission to convert anyone who asks regardless of the social or personal context of the request - often without even a hint of commitment to observance. Obtaining a conversion through such a court (even if you're entirely and honestly dedicated to Torah practice and values) will leave a cloud of doubt over the Jewishness of both you and all your descendants. In other words, if you want to do it, you surely want to do it correctly.
Also, becoming a Jew carries with it a great burden. We haven't been the most popular nation over the centuries (as you've no doubt noticed) and there's no guarantee that things will always be as comfortable as they now are for us (at least in the West).
Further, while not all Jews are perfect in observing the commandments of the Torah, these commandments are fully binding nonetheless and negligence carries serious consequences - both in this world and the next. We who are born Jewish have no choice and must do the best we can, but to choose it for yourself (while an act of great idealism) is a huge risk.
The road to Judaism is a very difficult one. For a sincere individual, there is the potential for greatness and for some there might even be a sense of coming home. But it isn't written anywhere that this is a road that must be taken or that there's no other way to find our one God