The line of Jesus is simpler, although many have struggled with these genealogies in the Bible. You will see in the above post the direction Muhammad takes from Abraham, namely through Ishmael.

The Biblical text traces the Christ through Isaac, as follows: (Luke 3, Matthew 1)

A. Luke 3:

Jesus ... the son (as was supposed) of Joseph, the son of Heli, the son of Matthat, the son of Levi, the son of Melchi, the son of Jannai, the son of Joseph, the son of Mattathias, the son of Amos, the son of Nahum, the son of Esli, the son of Naggai, the son of Maath, the son of Mattathias, the son of Semein, the son of Josech, the son of Joda, the son of Joanan, the son of Rhesa, the son of Zerubbabel, the son of Shealtiel, the son of Neri, the son of Melchi, the son of Addi, the son of Cosam, the son of Elmadam, the son of Er, the son of Jesus, the son of Eliezer, the son of Jorim, the son of Matthat, the son of Levi, the son of Symeon, the son of Judas, the son of Joseph, the son of Jonam, the son of Eliakim, the son of Melea, the son of Menna, the son of Mattatha, the son of Nathan, the son of David, the son of Jesse, the son of Obed, the son of Boaz, the son of Salmon, the son of Nahshon, the son of Amminadab, the son of Arni, the son of Hezron, the son of Perez, the son of Judah, the son of Jacob, the son of Isaac, the son of Abraham...

Luke knew the truth of the matter. It was only "supposed" that Jesus' Father was Joseph. That's what people thought. Luke knew that Jesus is the Son of God. He gave this genealogy of Mary's line to show that in His flesh He was indeed also the "Son of David" long prophesied to come into the world.

Why do the scholar's say that Luke's list is "Mary's" line? Well, Matthew has already established that Joseph's father was one named Jacob. See below. Here he is called "Heli." Not only is Heli different, but all the names from here back to David are too.

The answer seems relatively simple. Matthew traces through Solomon a legal lineage. Jesus is the Son of David in both lines, but Solomon was told that the Kingdom would be taken from him, and eventually the Jewish Kings were told that no one in that line would rule again. So how to have a Ruling Messiah from David without coming against the revealed word of God? You have Him come from another son of David. You'll see his name in Luke: Nathan (not to be confused with the prophet by that name).

So both genealogies are valid and true. One shows his legal rights, the other His blood rights. And He shall rule the Throne of David on the basis of the promise, not the human line of the Throne of Israel. It's all in these two genealogies, along with a lot more, had we the time.

B. Here's Matthew's version:

Abraham begat Isaac; and Isaac begat Jacob; and Jacob begat Judah and his brethren; and Judah begat Perez and Zerah of Tamar; and Perez begat Hezron; and Hezron begat Ram; and Ram begat Amminadab; and Amminadab begat Nahshon; and Nahshon begat Salmon; and Salmon begat Boaz of Rahab; and Boaz begat Obed of Ruth; and Obed begat Jesse; and Jesse begat David the king. And David begat Solomon of her that had been the wife of Uriah; and Solon of her that had been the wife of Uriah; and Solomon begat Rehoboam; and Rehoboam begat Abijah; and Abijah begat Asa; and Asa begat Jehoshaphat; and Jehoshaphat begat Joram; and Joram begat Uzziah; and Uzziah begat Jotham; and Jotham begat Ahaz; and Ahaz begat Hezekiah; and Hezekiah begat Manasseh; and Manasseh begat Amon; and Amon begat Josiah; and Josiah begat Jechoniah and his brethren, at the time of the carrying away to Babylon. And after the carrying away to Babylon, Jechoniah begat Shealtiel; and Shealtiel begat Zerubbabel; and Zerubbabel begat Abiud; and Abiud begat Eliakim; and Eliakim begat Azor; and Azor begat Sadoc; and Sadoc begat Achim; and Achim begat Eliud; and Eliud begat Eleazar; and Eleazar begat Matthan; and Matthan begat Jacob; and Jacob begat Joseph the husband of Mary, of whom was born Jesus, who is called Christ.

So how do Muhammad and Jesus the Christ compare in genealogy? First, the genealogies of Islam are not certain. We believe that it was through the Spirit of God that we were given Luke and Matthew.

Second, giving Islam the benefit of the doubt, and allowing that Muhammad was the descendant of Ishmael, and given that Jesus is the descendant of the Promised Son, Isaac, we are left with the very real distinction suggested.

While Muhammad is never hinted at in Scripture, still we see in the people that were to come from Ishmael a glimpse into their future state:

Ishmael himself was to be a "wild man; his hand shall be against every man, and every man's hand against him. And he shall dwell in the presence of all his brethren."

Also, God says, "I have blessed him, and will make him fruitful, and will multiply him exceedingly..." We can't forget that part.

"But my covenant," He says in the next breath, "I will establish with Isaac..."

The promise of the land. The promise of incredible blessing. And a great people. In fact, in Abraham, and then in Isaac (Genesis 26:4) all the families of the earth are to be blessed. The promise was not fulfilled in Abraham or Isaac, or any sons of that era. The world has yet to see what this shall fully mean. But it is clear that Jesus Christ, Isaac's descendant, is poised and ready to fulfill this promise upon His return. Already this one Man has brought incredible blessing to untold millions through the years. But the best is yet to come, and it's in Jesus.

Isaac is a man of peace, who is looked after by the Father in the Father's desire that he be given a proper bride, namely Rebekkah. In all of this he is a picture of the coming Christ.

Muhammad has been given material blessing. But the price for that blessing to the rest of the world has been horrendous. God may be using "Ishmael's" greatness to purge the earth somewhat before Jesus comes with the final purge, but when Jesus comes, after that initial judgment, there shall be no more sin, no more sickness, eventually no more death. Then shall it truly be said that all the nations of the earth shall be blessed.

Genealogies are important! Jesus is the true Son of the Promise. As great as Isaac is over Ishmael so Jesus is over Muhammad, and infinitely more, since He is God Almighty in addition!