Maybe you should re-read Peter’s sermon. Where do you find him speaking of Christ’s death as GOOD NEWS? He didn’t. He BLAMED Israel for Christ’s death. That is not preaching the gospel of the grace of God. In no way.
22 “Men of Israel, listen to these words: Jesus the Nazarene, a man attested to you by God with miracles and wonders and signs which God performed through Him in your midst, just as you yourselves know— 23 this Man, delivered over by the predetermined plan and foreknowledge of God, you nailed to a cross by the hands of godless men and put Him to death. 24 But God raised Him up again, putting an end to the agony of death, since it was impossible for Him to be held in its power.
After this Acts records they were "were pierced to the heart." So we have the death and Resurrection of Jesus Christ preached by Peter.
Acts 3:
12 But when Peter saw this, he replied to the people, “Men of Israel, why are you amazed at this, or why do you gaze at us, as if by our own power or piety we had made him walk? 13 The God of Abraham, Isaac and Jacob, the God of our fathers, has glorified His servant Jesus, the one whom you delivered and disowned in the presence of Pilate, when he had decided to release Him. 14 But you disowned the Holy and Righteous One and asked for a murderer to be granted to you, 15 but put to death the Prince of life, the one whom God raised from the dead, a fact to which we are witnesses. 16 And on the basis of faith in His name, it is the name of Jesus which has strengthened this man whom you see and know; and the faith which comes through Him has given him this perfect health in the presence of you all.
17 “And now, brethren, I know that you acted in ignorance, just as your rulers did also. 18 But the things which God announced beforehand by the mouth of all the prophets, that His Christ would suffer, He has thus fulfilled. 19 Therefore repent and return, so that your sins may be wiped away, in order that times of refreshing may come from the presence of the Lord; 20 and that He may send Jesus, the Christ appointed for you, 21 whom heaven must receive until the period of restoration of all things about which God spoke by the mouth of His holy prophets from ancient time. 22 Moses said, ‘The Lord God will raise up for you a prophet like me from your brethren; to Him you shall give heed to everything He says to you. 23 And it will be that every soul that does not heed that prophet shall be utterly destroyed from among the people.’ 24 And likewise, all the prophets who have spoken, from Samuel and his successors onward, also announced these days. 25 It is you who are the sons of the prophets and of the covenant which God made with your fathers, saying to Abraham, ‘And in your seed all the families of the earth shall be blessed.’ 26 For you first, God raised up His Servant and sent Him to bless you by turning every one of you from your wicked ways.”
Again, Peter preaches the death and resurrection of Jesus Christ.
Continuing in Acts 4:
5 On the next day, their rulers and elders and scribes were gathered together in Jerusalem; 6 and Annas the high priest was there, and Caiaphas and John and Alexander, and all who were of high-priestly descent. 7 When they had placed them in the center, they began to inquire, “By what power, or in what name, have you done this?” 8 Then Peter, filled with the Holy Spirit, said to them, “Rulers and elders of the people, 9 if we are on trial today for a benefit done to a sick man, as to how this man has been made well, 10 let it be known to all of you and to all the people of Israel, that by the name of Jesus Christ the Nazarene, whom you crucified, whom God raised from the dead—by this name this man stands here before you in good health. 11 He is the stone which was rejected by you, the builders, but which became the chief corner stone. 12 And there is salvation in no one else; for there is no other name under heaven that has been given among men by which we must be saved.”
Continuing to Acts 5:
29 But Peter and the apostles answered, “We must obey God rather than men. 30 The God of our fathers raised up Jesus, whom you had put to death by hanging Him on a cross. 31 He is the one whom God exalted to His right hand as a Prince and a Savior, to grant repentance to Israel, and forgiveness of sins. 32 And we are witnesses of these things; and so is the Holy Spirit, whom God has given to those who obey Him.”
In Acts 8 we have Philip preach the Gospel from Isaiah 53:
Acts 8:
30 So Philip ran to him, and heard him reading the prophet Isaiah, and said, “Do you understand what you are reading?”
31 And he said, “How can I, unless someone guides me?” And he asked Philip to come up and sit with him. 32 The place in the Scripture which he read was this:
“He was led as a sheep to the slaughter; And as a lamb before its shearer is silent, So He opened not His mouth. 33 In His humiliation His justice was taken away, And who will declare His generation? For His life is taken from the earth.”
34 So the eunuch answered Philip and said, “I ask you, of whom does the prophet say this, of himself or of some other man?” 35 Then Philip opened his mouth, and beginning at this Scripture, preached Jesus to him. 36 Now as they went down the road, they came to some water. And the eunuch said, “See, here is water. What hinders me from being baptized?”
37 Then Philip said, “If you believe with all your heart, you may.”
And he answered and said, “I believe that Jesus Christ is the Son of God.”
38 So he commanded the chariot to stand still. And both Philip and the eunuch went down into the water, and he baptized him. 39 Now when they came up out of the water, the Spirit of the Lord caught Philip away, so that the eunuch saw him no more; and he went on his way rejoicing. 40 But Philip was found at Azotus. And passing through, he preached in all the cities till he came to Caesarea.
The above seems to be consistent with the previous messages spoken on the gospel of Christ crucified, died and risen from the dead.
Seems Paul preached this same gospel:
Acts 9:
20 Immediately he preached the Christ in the synagogues, that He is the Son of God.
21 Then all who heard were amazed, and said, “Is this not he who destroyed those who called on this name in Jerusalem, and has come here for that purpose, so that he might bring them bound to the chief priests?”
22 But Saul increased all the more in strength, and confounded the Jews who dwelt in Damascus, proving that this Jesus is the Christ.
And if that is not convincing enough, Paul stated clearly that he preached the same gospel as did Peter and 11:
1 Corinthians 15:
15 Moreover, brethren, I declare to you the gospel which I preached to you, which also you received and in which you stand, 2 by which also you are saved, if you hold fast that word which I preached to you—unless you believed in vain.
3 For I delivered to you first of all that which I also received: that Christ died for our sins according to the Scriptures, 4 and that He was buried, and that He rose again the third day according to the Scriptures, 5 and that He was seen by Cephas, then by the twelve. 6 After that He was seen by over five hundred brethren at once, of whom the greater part remain to the present, but some have fallen asleep. 7 After that He was seen by James, then by all the apostles. 8 Then last of all He was seen by me also, as by one born out of due time.
9 For I am the least of the apostles, who am not worthy to be called an apostle, because I persecuted the church of God. 10 But by the grace of God I am what I am, and His grace toward me was not in vain; but I labored more abundantly than they all, yet not I, but the grace of God which was with me. 11 Therefore, whether it was I or they, so we preach and so you believed.