The verse from Isaiah 53:7-8 was perplexing the eunuch and he asked Philip to guide him as to its meaning:

"He was oppressed, and he was afflicted, yet he opened not his mouth: he is brought as a lamb to the slaughter, and as a sheep before her shearers is dumb, so he openeth not his mouth" (Isa.53:7).

Sir Robert Anderson says, "'He was oppressed, yet He humbled Himself and opened not His mouth; as a lamb that is led to the slaughter, and as a sheep that before her shearers is dumb, yea He opened not His mouth' (Isaiah liii. 7, R.V.). There is a general consensus of opinion that to this passage it is that the Baptist’s words refer (Jn. i. 29). And it is noteworthy that it contains no sacrificial language ; for, in the Hebrew, 'slaughter' is a common word that points to the shambles. It foretold the Messiah’s earthly life of humiliation and suffering" (Anderson, Misunderstood Texts of the New Testament, p.59).

There certainly is no indication that the eunuch ever understood that Isaiah 53:7-8 was showing that Christ would die for our sins after Philip "preached unto him Jesus". He asked to be baptized, and Philip told him that he could if he believed. In answer, the eunuch did not say, "I believe that Jesus died for my sin" but instead replied that "I believe that Jesus Christ is the Son of God" (Acts 8:37).

"And he took the cup, and gave thanks, and gave it to them, saying, Drink ye all of it; For this is my blood of the new testament, which is shed for many for the remission of sins" (Mt.26:27-28).

There is no evidence that the Apostle understood the meaning of the Lord Jesus' words here on the eve of His crucifixion to be referring to the fact that "He hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him" (2 Cor.6:21).

Instead, the Apostles would be aware of the Scriptures that promises to the house of Israel a "New Covenant", and according to that promise the Lord would "remember their sins no more" (Jer.31:34). Therefore when the Lord Jesus said that "This cup is the new testament in my blood (Lk.22:20) they would understand that His death was the "earnest" or "surety" of the New Teatament. Charles Spurgeon said that "the blood is the symbol, the token, the earnest, the surety, the seal of the covenant" (Spurgeon, Sermon delivered on September 4th, 1859,#273).

"For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures; And that he was buried, and that he rose again the third day according to the scriptures" (1 Cor.15:3-4).

Some believers say that the OT Scriptures revealed that Christ "died for our sins" because Paul wrote that the Lord Jesus died for our sins "according to the Scriptures". Notice that Paul also says that He rose again the third day "according to the Scriptures." The OT Scriptures will be searched in vain for any testimony that the Messiah would be buried and then rise from the dead "the third day". What Paul is saying is that the evidence of these things can be found in the "types" of the OT but these truths were not openly revealed. It was not until the Lord Jesus said that "For as Jonas was three days and three nights in the whale's belly; so shall the Son of man be three days and three nights in the heart of the earth (Mt.12:40) that anyone understood that the Scriptures in regard to Jonas were a "type" of the death and resurrection of the Lord Jesus. It was not until after the Cross that anyone understood that the OT sacrifices were a "type" of the Lord Jesus dying for our sins.

"Even the mystery which hath been hid from ages and from generations, but now is made manifest to his saints: To whom God would make known what is the riches of the glory of this mystery among the Gentiles; which is Christ in you, the hope of glory" (Col.1:26-27).

Some believers say that "the mystery" is "Christ in you, the hope of glory". However, here Paul is speaking of the "riches" that flow from the "mystery", and among those riches is Christ in you, the hope of glory.