Question: Why do genealogies of Jesus differ so greatly between Matthew 1 and Luke 3? A guest lecturer at a local university, speaking about the religion of Islam, pointed out the "discrepancies" between the two Gospels as a reason not to put faith in the Bible but rather to trust in the Koran.
Discussion: Your question interests me greatly, so I'd previously done some research on it with the hope of exploring the topic in a book. Since I'll refrain from going to that length here, I'll give you a few answers that satisfied me. For instance, prior to writing his Gospel, Luke reportedly "interviewed" Mary. Of all the Gospel writers his is the account that most focuses on Mary and so his genealogy reflects her heritage rather than Joseph's. Since she's the human being through whom Jesus physically arrived a physician like Luke would probably have been quick to inquire about her background and, like a good doctor, take ample notes.
Besides that possibility, variations in languages, translations, and spellings confuse the issue, so some names that seem to conflict may not. For example, where Matthew (1:4)Â named only Amminadab, Luke (3:33) listed Admin and Amminadab, which could be different renderings of the same Hebrew name, Amminadav. Nicknames could have been substituted in some instances, and the names of a better known or more respected son may have been emphasized too. Also, Abram (later known as Abraham) and Sarai (later Sarah) and Jacob (later Israel) attest to previous occasions when God has given new names to people renewed in their faith.
The overall goal of each writer might be yet another factor to consider. i.e., because each writer accentuated whatever interested him the most or whatever he felt compelled to report, variations in the accounts bring vivid details that give a broader understanding of the whole truth. For instance, Luke wanted to show that Christ came for all peoples, so his genealogical account goes back to Adam and the beginnings of mankind. By contrast, but not conflict, Matthew primarily wrote to convince Jewish readers that Jesus was the long-awaited Messiah. Therefore, he emphasized Jesus' genealogy through Abraham, who was the father of Isaac, grandfather of Jacob, and great-grandfather of Judah through whom came the Jews. Abraham also fathered Ishmael through whom came the Muslims in particular and Arabs in general, so as you read Genesis 16 and 21, you'll see how this begat quarrels from the start.
Apparently, those conflicts continue. Since your instructor injected the Koran to reject the Bible and, ultimately, refute Judaism, the law of Moses (or Ten Commandments), Jesus Christ, Christianity, and the Church, I'm compelled to point out that Holy Scripture came not as an already completed document but as the living word from our living God. From the beginning, the Holy Spirit inspired the writings and the relationships of highly diverse peoples with one loving but Holy God, so it's not surprising that Jesus' genealogy shows this diversity. For example, peoples of another faith might not want to mention a lineage or "pedigree" that includes a prostitute (Rahab), alien (Ruth), adulteress (Bathsheba), and an unwed mother (Mary) in addition to the many forefathers who lied, murdered, and slept around. Most individuals and religions would bury such details, but the Bible does not cover or gloss over the truth, no matter how unpleasant it may seem.
It becomes obvious, then, why the pure word of the purely Holy Spirit allowed impurities to be mentioned — simply because it's the truth. But why does Holy Scripture highlight flawed characters in the lineage of God's only Son? Could it be to show us how perfectly our perfect God works in and through imperfect people despite our imperfections and failures? Could it be God reminds us that we cannot, as Christians, claim to be a perfect people, but thanks to our Savior Jesus Christ and the Sacrament of Reconciliation in his Body, the Church, we can be called a forgiven people?
Frankly, I don't know what the Koran has to say about forgiveness since I've never read the book, but I have heard that it's silent on the subject — the very subject most needed by every person on earth. By contrast, the Bible repeatedly assures us of God's redemption. The Holy Scriptures also assure us that, while every created person and every thing in creation will eventually change in some way, God the Creator does not. Our relationship with the living God transforms and deepens as we come to know the Father, the Son, and the Holy Spirit, but our Holy God has no need to change his own perfection. So, when the Bible says in Hebrews 13:8 that "Jesus Christ is the same yesterday, today, and forever," we know this is something only God can be — unchanging.
As the son of Mary, Jesus became fully human with a physical body and a family background that may be as difficult to discern or decipher as our own genealogies, but Jesus has another heritage too. As the only Son of God, Jesus Christ has been given the authority, power, and good pleasure to forgive, restore, and adopt us into his family — the chosen family of the one, true, living, loving, Holy God.
