Short answer
Neither, by his own words. Luke opens his Gospel by saying that many others had already written accounts. He says the eyewitnesses handed the story down to him, so he was not one of them. He then says he studied it all with care and decided to write it out in order for a man named Theophilus. He never says that God (﷾) gave him his words. That is how a historian writes, not a prophet. Paul, a Christian missionary of the first century, also marks some of his advice as his own and not the Lord's. The Qur'an makes the opposite claim for itself: every word of it is revelation.
Full explanation
Luke's own opening
The first three verses of the Gospel of Luke are the writer's own account of his method. He names "many" earlier writers. He says the eyewitnesses "delivered" the story to "us". That places him among those who received it, not those who saw it. His reason for writing is that "it seemed good" to him, after his own study. The book is addressed to one man. There is no "thus saith the LORD" and no claim of a vision. A Christian may say God (﷾) guided Luke as he studied. But Luke himself never says so.
“Forasmuch as many have taken in hand to set forth in order a declaration of those things which are most surely believed among us, Even as they delivered them unto us, which from the beginning were eyewitnesses, and ministers of the word; It seemed good to me also, having had perfect understanding of all things from the very first, to write unto thee in order, most excellent Theophilus,”
What the Greek of verse 3 says
A modern public-domain translation shows the sense of the Greek plainly. Luke had "traced the course of all things accurately from the first". The Greek word here is anothen. Elsewhere it can mean "from above". Here it follows the eyewitnesses who were there "from the beginning" in verse 2. So it describes how far back his research went. It is not a message from above.
“Since many have undertaken to set in order a narrative concerning those matters which have been fulfilled among us, even as those who from the beginning were eyewitnesses and servants of the word delivered them to us, it seemed good to me also, having traced the course of all things accurately from the first, to write to you in order, most excellent Theophilus;”
Who Luke was
Church tradition, which the evangelical NIV Study Bible follows, identifies the writer with Luke, the physician Paul mentions among his companions. He was not one of the twelve, Jesus' closest followers. Paul himself never met Jesus during his ministry. The same writer addresses Acts to Theophilus too.
The evangelical NIV Study Bible's introductions hold to the traditional authors, but grant that the books themselves do not name them. On Mark: there is no direct evidence inside the book of who wrote it; the name rests on the testimony of the early church. On Luke: the name of the writer does not appear in the book (it adds that other evidence points to Luke). On John: the apostle is not named anywhere in the Gospel, and the notes argue for him from that silence.
“Luke, the beloved physician, and Demas, greet you.”
“The former treatise have I made, O Theophilus, of all that Jesus began both to do and teach,”
Paul also marks his own words
Luke is not alone. Paul tells the Corinthians that one ruling is his, "not the Lord". On another question he has "no commandment of the Lord" and gives his own judgment. He ends the chapter with "after my judgment". He adds only that he thinks he has the Spirit of God (﷾). He himself separates the Lord's command from his own opinion.
“But to the rest speak I, not the Lord: If any brother hath a wife that believeth not, and she be pleased to dwell with him, let him not put her away.”
“Now concerning virgins I have no commandment of the Lord: yet I give my judgment, as one that hath obtained mercy of the Lord to be faithful.”
“But she is happier if she so abide, after my judgment: and I think also that I have the Spirit of God.”
| Verse | The words | Who is speaking, by the verse itself |
|---|---|---|
| Luke 1:2 | “even as they delivered them unto us, which from the beginning were eyewitnesses” | Luke, who received the story from eyewitnesses. He was not one of them. |
| Luke 1:3 | “It seemed good to me also … to write unto thee in order” | Luke, writing after his own study, for one man, Theophilus |
| 1 Corinthians 7:12 | “But to the rest speak I, not the Lord” | Paul, not the Lord |
| 1 Corinthians 7:25 | “I have no commandment of the Lord: yet I give my judgment” | Paul, giving his own judgment |
| 1 Corinthians 7:40 | “after my judgment: and I think also that I have the Spirit of God” | Paul, giving his own judgment. He adds that he thinks he has the Spirit of God (﷾). |
In these verses, neither writer says that God (﷾) gave him the words. The Qur'an claims the opposite for itself: every word of it is revelation.
The Qur'an claims every word
The Qur'an says of the Prophet (ﷺ) that he does not speak from his own desire. What he brings is revelation sent down to him. Islam keeps this line clear. The Qur'an holds only the words of God (﷾). The Prophet's (ﷺ) own sayings are kept apart as hadith (reports of what he said and did) and are never recited as Qur'an. Muslims hold that God (﷾) guided these too, but they are not recited as His word.
“Nor does he say (aught) of (his own) Desire. It is no less than inspiration sent down to him:”
Verse by verse
2 Timothy 3:15-16 — Second Epistle to Timothy, chapter 3, verses 15-16
“And that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus. All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness:”
Cited for
Christians read "all scripture is given by inspiration of God" as covering the whole Bible, Luke included.
The response
The verse names no book. The scriptures in view are the ones Timothy had known "from a child". For a Jewish child those were the Hebrew Bible. Nothing in the verse says Luke's Gospel is among them. When Timothy was a child, not one book of the New Testament had yet been written.
Where it lands — The verse names no book and does not say that Luke is scripture.
1 Timothy 5:18 — First Epistle to Timothy, chapter 5, verse 18
“For the scripture saith, Thou shalt not muzzle the ox that treadeth out the corn. And, The labourer is worthy of his reward.”
Cited for
Christians say 1 Timothy quotes Luke 10:7 and calls it scripture, so Luke's Gospel was treated as scripture very early.
The response
The letter quotes a short saying of Jesus, not Luke's book by name. The saying could have been known without it. Even if it were Luke, another writer's label cannot outweigh Luke's own opening. There he says he wrote from his research for Theophilus.
Where it lands — Luke's own account of how he wrote stands; another writer's label does not turn research into revelation.
Luke 1:1-3 — Gospel of Luke, chapter 1, verses 1-3
“Forasmuch as many have taken in hand to set forth in order a declaration of those things which are most surely believed among us, Even as they delivered them unto us, which from the beginning were eyewitnesses, and ministers of the word; It seemed good to me also, having had perfect understanding of all things from the very first, to write unto thee in order, most excellent Theophilus,”
Cited for
Some Christians render Luke's word for "from the first" as "from above", as if Luke claimed knowledge given from heaven.
The response
The word anothen can mean "from above", as in John 3:31, but it also means "from the beginning". Here the sentence decides. Luke says he traced everything back. He sets this beside the eyewitnesses who were there "from the beginning" in verse 2. The King James Version reads "from the very first" and the World English Bible "from the first".
Where it lands — Luke describes how far back he traced the story, not a revelation.
Perspectives
Mainstream Christian
Luke did careful research, and the Holy Spirit guided him as he wrote. So his Gospel is both good history and the inspired word of God. Scripture itself says all scripture is inspired.
2 Timothy says that all scripture is given by inspiration of God.
Rebuttal
Grant that the verse says all scripture is inspired. It names no book. The scriptures Timothy knew from a child were the Hebrew Bible, because no New Testament book yet existed. Nothing in the verse puts Luke's Gospel among them.
1 Timothy calls "the labourer is worthy of his reward" scripture, a saying also found in Luke 10:7.
Rebuttal
Grant that the saying is also in Luke 10:7. The letter quotes a short saying of Jesus, not Luke's book by name. Another writer's label cannot outweigh Luke's own opening, where he says he wrote from his research.
The Islamic perspective
Luke was an honest writer of history who did not claim revelation. Human writing, however good, should not be called the word of God (﷾). The Qur'an alone claims that every word in it came from God (﷾).
Luke says the eyewitnesses handed the story down to him, so he was not an eyewitness.
Luke gives his own research and judgment as his reason for writing, and claims no revelation.
Paul marks some of his rulings as his own judgment, "not the Lord". On one question he says he has "no commandment of the Lord".
The Qur'an claims that everything the Prophet (ﷺ) brought as revelation is from God (﷾). None of it, it says, came from his own desire.