Of course it is. If anyone calls themselves a Christian, that means they follow the Lord Jesus Christ & continues to abide in His words/teaching.
Did Jesus teach there was an actual Adam & Eve in the very beginning? Indeed He did. He created them! He was there in the beginning. So the problem is not in Genesis, the problem is with Jesus. If one does not believe what Jesus taught is true & as His disciple, teaching people to observe all that He commanded, then how can they call themselves a 'Christian?' Jesus said that identified a follower of His.
When tested by the Pharisees on divorce, Jesus said the following:
“Have you NOT read that from the beginning the Creator ‘made them male & female’ & said, ‘For this reason a man will leave his father & mother & be united to his wife & the two will become one flesh’ ? So they are no longer two, but one flesh. Therefore what God has joined together, let man not separate.”
The creation of the first man & woman, Adam & Eve was done by Jesus! He refers them back to Genesis & says that is exactly what happened. The whole institution of marriage is also cited, from Genesis 2, again referring to this same first created male & female & it says they were named Adam & Eve.
Our whole foundation of Christianity is based on the apostles & the prophets & what they wrote, with Christ being the chief cornerstone.
Paul plainly taught that all mankind came from one man & that one man in revelation from God was Adam. (Acts 17). He again verifies Genesis 10, the table of nations. Others have shown other places where Paul demonstrates this.
Romans 5 is another passage that a literal Adam, one man, the first Adam brought sin & death into the world & as a result all human beings have died. Death is not an allegory or an illusion! People literally die!
Christ, as the Last Adam or man died on a cross to set us free from the law of sin & death & came to give us His eternal life. I Cor 15 is another vital passage. Christ actually did literally rise out from among the dead & we too, as faithful followers of Christ will also be literally resurrected again, to live with Christ forever. All this ties in with a literal Adam.
The Apostle Paul, who by the way received his teachings as direct revelation from Jesus Christ Himself, taught that the woman, Eve, actually did literally come from the man, Adam, just as the Genesis account reveals, in I Corinthians 11.
The prophet Malachi taught we all have one father & one Creator & he also talks about the institution of marriage & being faithful to the wife of one's youth (Malachi 2).
The Biblical writer, Jude, the brother of Jesus, also mentions Adam and that Enoch was the literal 7th descendant from Adam & this agrees with the Genesis account.
The genealogy of Jesus Christ goes all the way back to Adam! Jesus had to have a literal genealogy of literal people to demonstrate & show He was a biological and legal descendant of king David & Abraham & the true prophesied Messiah.
If one doesn't believe Jesus, or the prophets, if one doesn't believe the apostles, if one doesn't believe the Bible as the inspired revelation of God, the word of truth, then why in the world would someone presume to call themselves a Christian, & try to identify as a follower of Christ & what He taught, yet don't believe what He taught is true?