This was the etymological information they provided:

The classical Latin adjective "spurius" started out as a word meaning  "illegitimate." In the days of ancient Rome, it was sometimes even used as a  first name for illegitimate offspring (apparently with no dire effects). There  was a certain Spurius Lucretius, for example, who was made temporary magistrate  of Rome. In less tolerant times, 18th-century English writer Horace Walpole  noted that Henry VII "came of the spurious stock of John of Gaunt." Today, we  still use "spurious" to mean "illegitimate," but the more common meaning is  "false" (a sense introduced to "spurious" in Late Latin). Originally our "false"  sense emphasized improper origin, and it still often does ("a spurious  signature"), but it can also simply mean "fake" or "not real."

Judaism of today often claims an illegitimate birth of Yeshua supposing that Mary was raped by a Roman soldier.  The Gospels tell us otherwise proclaiming that G-d Himself caused Mary to become pregnant.  This was not through some physical union as claimed by some but by a supernatural act of G-d.  Just as G-d created Adam in a supernatural manner, so, too was Yeshua created in a supernatural way.  (See Luke 1:26-38)

We are warned in Scripture to beware false (or illegitimate) prophets (Matthew 7:15, 24:11) and false messiahs (Mark 13:22, 24:23-26).

Be on guard that you do not place your faith in a false messiah... in a man who never existed.  If I said Jesus was a 3-foot tall alien from the planet Zurghloth most (rational) believers would immediately reject that teaching as false.  In a similar manner we should reject any teaching that Messiah Yeshua came to do away with the Law.  He, Himself, instructed us not to think such a thing:

Do not think that I came to abolish the Law or the Prophets; I did not come to abolish but to fulfill. (Matthew 5:17)

When we claim to have faith in Jesus/Yeshua we should know in whom we are placing our faith and study to ensure that we have not placed that faith in a spurious messiah.

To Him who sent the True Vine (John 15:1) and the true Messiah be the honor and glory forever.  Amen.