The Preface to Luke's Gospel: the Critics

There is nothing inconsistent with the thought of inspiration in the full sense of the word in Luke 1:1-4. "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, that thou mightest know the certainty of those things, wherein thou hast been instructed."
Infidels have asserted that inspiration was not required to record matters of history and biography. In a general sense this may be true, but inspiration insures perfect accuracy in the record, which no unaided historian can afford. But it has been asserted that Luke admits his own non-inspiration. He does nothing of the kind. In these verses we find three sources of information whereby we may know those things that concern the life of our blessed Lord and Savior.
First and foremost there are those who "from the beginning were eyewitnesses"; these were the apostles who narrated the facts of our Lord's life, death, resurrection, and ascension, not merely as intelligent men, but as "ministers of the word." In other words, "their oral testimony was inspired."
In the second place, there were those who undertook to set down in writing the things communicated to them by these inspired apostles--things which were received among the Christians with full certainty ("surely believed").
These many writers, while pious in their motives, were nevertheless not inspired writers.
The apostolic oral testimony of verse 2 had given to the many writers of verse 1, and to the whole Christian company of that time, a sure ground of belief. But for the good of the whole Church in all ages something further was needed, and this we have in the four inspired gospels.
Hence we have in the third place the written testimony of Luke (vv. 3, 4), who contrasts
himself with the writers of verse 1, and compares himself with the inspired apostles of verse 2. His motive was not only a pious one, but was divinely directed in its execution, so that believers in all ages might "know the certainty of those things." Luke had what the writers of verse 1 had not; namely, "perfect understanding of all things from the very first." Luke, therefore, did not need what the others did before he could write; he did not require to be told the facts by the apostles; he himself had a perfect understanding of every detail from the very commencement. This was a claim to absolute accuracy which could only be by divine inspiration.
A Reader Inquires
ANSWER: The sure mercies of David are mentioned twice: "Incline your ear, and come unto Me: hear, and your soul shall live; and I will make an everlasting covenant with you, even the sure mercies of David." Isa. 55:3. "And as concerning that He raised Him up from the dead, now no more to return to corruption, he said on this wise, I will give you the sure mercies of David. Wherefore He saith also in another psalm, Thou shalt not suffer Thine Holy One to see corruption." Acts 13:34, 35.
It is evident from these scriptures that the sure mercies of David are connected with Christ in resurrection. Isa. 53 gives us the rejection of Christ by Israel, His substitutionary work, His resurrection and exaltation; then chapter .54 gives some of the results for Israel, and chapter 55 exhorts and encourages on this groundwork; hence the "sure mercies of David" come in here.
In Acts 13 the same theme is discovered, for the previous verse, the 33rd, tells us that God fulfilled the promises made to the fathers when He raised up Jesus (not "again," but raised Him up by sending Him into this world- incarnation) according to the word in the "second psalm, Thou art My Son, this day have I begotten Thee." Then in the 34th verse the Holy Spirit speaks of His being raised up from the dead, "now no more to return to corruption," and quotes Isa. 55:3 about the sure mercies of David to substantiate the unchangeableness of His resurrection and consequent blessing.
The 16th psalm is also called upon to render testimony to this truth: "Thou shalt not suffer Thine Holy One to see corruption."
There is a greater connection between "Thine Holy One" of the 35th verse and the "sure mercies of David" of the 34th verse than appears on the surface. They are practically the same word in the original language. Psalm 89 is a case in point. There in the first verse the psalmist says he will sing of the mercies of Jehovah, and in the 19th verse, "Thou spakest. to [or, of] Thy holy one." The only difference in the Hebrew text between "mercies" of the first verse and "holy" of the 19th verse is that the first is plural and the second singular. Thus all the mercies of God are centered in His Son, the holy, or merciful One. The same connection is to be found in Acts 13 between the "Holy One" of verse 35 and the "mercies" of verse 34.
Therefore, we can conclude that the mercies to Israel based on a Messiah coming through the seed of David were lost when they cried "away with Him" and chose "a murderer and a robber." But God, who foresaw all, promised them "sure" mercies through Him in whom all mercies center, but in Him risen and glorified. So if Israel rejected Christ, and with Him their own blessing, God will bring all to pass without fail in Him whom He raised from the dead, and who will never return to it. The promises of blessing to David through his heir were not sure in the sense that when they came (in the Person of Christ) they were rudely rejected, but they are made sure in Him-David's greater Son -in resurrection. "For all the promises of God in Him are yea, and in Him Amen"; or, they are affirmed in Him and will all be confirmed in Him (2 Cor. 1:20).