The proper way to teach Judaism to someone with a limited background, is to begin by making a picture of a mountain. The mountain would have two phrases, תורה שבכתב, and תורה שבעל פה, the Written Law and the Oral Law.
The mountain is Mount Sinai, of course, and this is where we began as a people. It is absolutely essential to accept that there was a revelation there, where every Jew was elevated to the level of prophecy, as they heard the first two of the Ten Commandments directly from Hashem. This is what makes Judaism both unique and Divine, as no religion ever began with several million people, hearing the voice of G-d.
It is equally important to accept and understand how the Writren and Oral Law are intertwined. We cannot truly understand the meaning of the Torah, without the Oral Law, that includes the teachings of the Rabbis, until today.
This is why one of the 613 Mitzvot is על פי התורה אשר יורוך, “According to the Torah that they will teach you.” Those who neglected the teachings of the Oral Law, and only followed the Torah literally, always failed. This has been proven throughout history, whether it was the Sadducees, Cuthites, Karaites, or Samaritans, they always remained on the fringe.
When one delves deeply into the Talmud, which the Maharal calls, “An exercise in the pursuit of truth,” he appreciates the special role played by the Rabbis in a practical application of the Torah.
We must remember the phrase that, “The Torah is perfect. Those who follow it are not.” But if there is a greater understanding of how the Written and Oral Law work together, more and more people will get it right.