The final authority for what Christians believe and how they behave is the Bible: "All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, so that the man of God may be thoroughly equipped for every good work." (2 Timothy 3:16-17)

For religious Jews the final authority lies with the traditions of the rabbis in the collection of books known as the Talmud. The Jewish Pirke Avot (The Ethics of the Fathers), begins: "Moses received the Torah on Sinai, and handed it down to Joshua; Joshua to the elders; the elders to the prophets; and the prophets handed it down to the men of the Great Synagogue."

When the Pirke Avot uses the word "Torah", it does not mean just the Ten Commandments. The word is variously used for the Law, the Five Books of Moses, the Old Testament Scriptures, as well as for the whole body of Jewish religious teaching, study and practice. According to the Pirke Avot, when God gave the written Law to Moses on Mount Sinai he also gave him the "Oral Law", an explanation of the meaning of the Law that Moses passed to Joshua, who handed it on to his successors who, in turn, delivered it to their successors. At the time of Christ this body of unwritten commandments was referred to as the "tradition of the elders" (Matthew 15:1-6).

In the fourth century AD these oral traditions began to be written and eventually became the Talmud, a huge collection of commentary and teaching by the rabbis. The modern Jewish scholar Jacob Neusner observes in Jews and Christians: The Myth of a Common Tradition that Christianity is the religion of the Bible, whereas Judaism is the religion of the Talmud.

Orthodox Jews believe the Talmud is as inspired as the Bible. So if one has a commentary and explanation that perfectly explains the Scriptures, why bother with the Bible? Therefore, most Jewish people are ignorant of what the Bible teaches. The Orthodox spend a great deal of time poring over texts in the rabbinic writings instead of reading the Scriptures. Most Jews never read the Bible at all except as part of synagogue worship and although they can read Hebrew fluently, many of them do not understand what they are reading.

Jacob Jocz, a Jewish Christian, has expressed the opinion that the major difference between Jews and Christians is the doctrine of the Trinity.

For Jewish people the basic text for their understanding of God is Deuteronomy 6:4: "Hear, O Israel: The LORD our God, the LORD is one". They refer to this statement as the Shema (pronounced sheh - mah), from the Hebrew word for "hear", shema. On the basis of this verse Jewish people throughout the ages have denied that God can be anything other than a single undivided unity. To Jews, the idea of one God in three Persons is idolatrous. 

However, there is more than one Hebrew word for "one". In Deuteronomy 6:4 the word is echad, which is used in Genesis 2:24 of Adam and Eve becoming "one flesh" and in Ezekiel 37:17 where two sticks are joined to become one. Echad is the word for a composite unity. If Moses had meant us to believe that God is absolutely one and indivisible he would have used the word yachid. Yet in the Middle Ages, the great Jewish thinker Moses Maimonides stated that God was "a single entity of a oneness even more single and unique than any single thing in creation" (a translation of Maimonides, Mishneh Torah, Mada 1:7) and, when he compiled what he referred to as the Shloshah-Asar Ikkarim (the Thirteen Articles of Faith), he ruled that those who followed Judaism could not believe that God was anything other than an absolute unity..

Judaism teaches that man is basically good. Although he has a Yetzer ha Ra, "the Evil Inclination" (which is probably a better term than the Christian "Original Sin"), he also possesses a Yetzer ha Tov, "the Good Inclination". By the study of God’s Law man can over come the evil inclination. Some Orthodox Jews believe that the evil inclination is a blessing from God because without it, they say, man would never be able to reproduce!

The Bible, on the other hand, teaches: "The LORD saw how great man's wickedness on the earth had become, and that every inclination of the thoughts of his heart was only evil all the time." (Genesis 6:5).

"The heart is deceitful above all things and beyond cure." (Jeremiah 17:9)

"Can the Ethiopian change his skin or the leopard its spots? Neither can you do good who are accustomed to doing evil." (Jeremiah 13:23)

Christians believe that salvation comes to us by God’s grace alone, through faith alone in Christ alone. The New Testament teaches that Abraham and all God’s people in the period of the Old Testament were saved by faith in the same way that we are (Romans 4; Galatians 3; Hebrews 11).

In the Old Testament (Leviticus 1-7; 16) an elaborate and complex sacrificial system was instituted to atone for sins. When an Israelite was conscious that they had broken a commandment of God they would bring a sacrificial animal to the priest, they would lay their hands of the head of the victim and confess their sins and by so doing transferred their guilt to the animal which then suffered the penalty of the sinner. Leviticus 17:11 says, "For the life of a creature is in the blood, and I have given it to you to make atonement for yourselves on the altar; it is the blood that makes atonement for one's life." This principle is the basis of the New Testament teaching that we are saved through the sacrificial shedding of the blood of Christ on the cross. 

In 70AD the temple in Jerusalem was destroyed. As a result, the priesthood and sacrifices ceased. This created a problem for the Jewish people. How were Jews to find forgiveness for their sins without a temple, a priesthood or sacrifices. One prominent rabbi, Jochanan ben Zakkai, announced that forgiveness could be found through repentance, based on one verse, Psalm 51:17: "The sacrifices of God are a broken spirit; a broken and contrite heart, O God, you will not despise." That has become the standard Jewish view of atonement.

The rabbis teach that at the Jewish New Year God weighs every man’s deeds in the balances of heaven. He inscribes the names of those who are totally righteous, who have not sinned, in the Book of Life (Jewish people send each other cards saying, "May you be inscribed for a good year"). Those who are absolutely wicked are inscribed for death. The rest of mankind who are "intermediate", neither totally evil nor totally righteous, have ten days to top up their store of good deeds by giving to charity and by study. At the end of the ten Days of Awe on the Day of Atonement Jewish people go to the synagogue to fast and repent for their sins in order that they may be inscribed in the Book of Life.

The Chief Rabbi of the United Hebrew Congregations of the Commonwealth, Dr. Jonathan Sacks, in a radio broadcast said that the greatest doctrine of Judaism is the teaching that the worst sinner can in an instant become the greatest saint by an act of his own free will. So modern Judaism, in all its forms, is a religion of self effort and good works.

If there is one belief common to Judaism, it is that Jesus was not the Messiah. Not all Jews believe in the coming of the Messiah. Some believe in a coming age of peace in which all men will live together as brothers. In the period of the New Testament the Jewish people were looking for a royal conqueror who would deliver Israel from the power of Rome (Acts 1:6), based on passages such as Psalm 110. Today, Jewish people are looking for a Messiah who will establish world wide peace, based on such passages as Isaiah 2:1-4; 11:1-9.

Now, as then, Jewish people have no concept of a Messiah who suffers for our sins (Acts 17:1-3; Matthew 16:21-23; Luke 24:25-27).

Jewish people generally do not know that the Hebrew prophets foretold where Messiah would be born (Micah 5:2); the miracle of his birth (Isaiah 7:14); his crucifixion (Psalm 22:12-18; Isaiah 53) or his resurrection (Psalm 16:9-11) etc.

Some of the ancient rabbis did recognise certain prophecies of a suffering Messiah. But because they could not reconcile those Scriptures with those that foretold a mighty conqueror they developed a theory of two Messiahs: Messiah ben David who conquers Israel’s enemies, and Messiah ben Joseph, who suffers and dies at the hands of Israel’s enemies.