Defining the Study:
Studying the Hebrew Roots of Christianity is not a study of Judaism nor is it a religious pursuit. It is an academic anthropological study of the Hebrew language, culture and belief structure that predates Judaism. Judaism, as the religion of the Jews, did not exist as such until about two centuries before Jesus was born in spite of what the Jewish Rabbis want the world to believe. Why?
The ancient Hebrews lacked the concept of a religion as separate thing from daily living or lifestyle. It was only under the cultural pressure from the invasion of the Greek, Egyptian and Roman cultures that there came to be this abstract notion that the Hebrew people had a 'religion.' Until then the Hebrews simply practiced a communal lifestyle that was compatible with their environment and honored Jehovah in everything they said and did. The Tabernacle and later the Temple was simply the focus of community life.
The Birth of the Jewish Religion:
So what about Judaism, the Pharisees and Sadducees? During the "biblically silent years," the four centuries before Jesus was born, historical documents first mention the Pharisees — and no earlier. In Jesus time, the Pharisees were in charge of all Torah observant acts and policies (interpretations of the Mosaic Law). The Sadducees were in charge of the Temple sacrifices and offerings, what they thought was the true religion of the Jews.
However, the Pharisees considered Judaism their personal domain and possession. Judaism became Phariseeism in those 'silent years'. The Pharisees claimed Jehovah gave an oral law in addition to the Law etched in stone given to Moses. They claimed that this oral law was superior to the written law since it was shouted from mount Sinai to all the people. They claimed their ancestors memorized this oral law and handed it down, father to son verbally. Since only the Pharisees knew this superior oral Law they felt authorized to clarify, adjust or modify the practice of the Mosaic Law (Torah Observance) and bind all Jews to their authority to do so.
Tenants of Pharisee Judaism:
1. There are two Torahs (one written, one oral)
2. Absolute Authority of Rabbis (superior to all the prophets)
3. Irrational Interpretation (Rabbis' right to make any passage say anything)
4. Sanctified Traditions (cultural habits become absolute law)
5. Right to add to Torah – that even God MUST OBEY
So what about the Sadducees? Sadducee is a westernized word for the Hebrew 'sons of Zadok,' the first high priest in Solomon's Temple. However, they differed from the Pharisees in two important aspects. The Sadducees were the priests carrying out the Temple services and activities. They did not seek to add to the Laws of Moses but only learned the rites of sacrifices and offerings, nothing more. Since they only concerned themselves with the Temple rites, they rejected the Pharisee's theological interpretations, oral law and their additions to the Mosaic Law. But not being theological thinkers, they were not looking for the coming Redeemer or the kingdom of God either. Hence they rejected resurrection into the kingdom which the Pharisees did believe in.
The Sadducees considered themselves the rightful successors of the Hebrew Monotheism. But since the Greek conquest (235 BCE) they began to favor Hellenizing the Hebrew culture. The Pharisees were thought of as a Jewish cult until the Sadducees fell into disfavor for their wealth and love of the Greek culture. The Pharisees were then seen as better keepers of the Mosaic Law, in spite of their arrogance to usurp Moses and dictate religious practice. The Pharisees usurped the Hebrew monotheism and Judaism was born.
Hebrew Cultural Anthropology
To study the Hebrew Roots of the faith, the Bible student must peer behind both of these two sects of Judaism, drop off religious studies and look back to the Hebrew culture before these sects arose. That's why studying the Hebrew Roots of Christianity is not a religious study but a Cultural Anthropology study of the ancient Hebrews. The Bible student must study the earlier culture, not the later religion. The Bible student must look for the base line lifestyle and the belief structures supporting the lifestyle.
Example: The Hebrews belief structure is reflected in their language which survives today. One characteristic of their belief structure is reflected in their use of language tenses. To them, if Jehovah said it, it was true and could now be spoken of as an established fact even if, humanly speaking, it was not seen. Such facts could then be spoken of in either the present tense or the past tense.
The apostle Paul, a Hebrew of the Hebrews, a Pharisee by education wrote this way all through his epistles. In the passage quoted below, Paul is speaking like Hebrew, even though it is written in Greek.
ESV: Ephesians Chapter 2  and raised us up with him and seated us with him in the heavenly places in Christ Jesus,
The ancient Hebrews had no concept of 'going to heaven' when you die (the Greeks and Egyptians did but not the Hebrews). To them, heaven was the sacred dwelling place of Jehovah. In the Hebrew mind, who discounts any thought that a human could live with God, he thinks "seated in the heavenly places with him" means two things. 'Seated' (past tense) means it is done or established. 'with him in the heavenly places' means God has written his name in the book of life (kept in heaven) or simply remembers him and thus establishes his place by resurrection in the future Promised Land, a place on earth a.k.a. the kingdom of God. The Hebrew thinks Paul is telling him his future life in the Kingdom of God is a done deal. Wow, talk about packing in a lot of meaning in a phrase! So what did the apostle Paul mean with this passage? Did he mean the Western interpretation or the Eastern? Let the theologians argue.
If you wish to study the Hebrew Roots of Christianity as a cultural study, avoid all authors who think Christianity is rooted in the religion of Judaism. Avoid everyone who thinks modern gentile Christians should make their gatherings or services look or sound like a Jewish synagogue. Look for scholars who write about the ancient Hebrew culture. Lastly, be very wary of authors who quote and reference Jewish rabbis!