Hogwash. There is one cross, one Christ, one finished work, one gospel POST-cross.
Prove that there is "one gospel POST-cross". Where did Peter preach in Acts 2 or 3 "how that Christ died for our sins" as the good news (gospel=good news)?
He didn't. Peter preached a murder indictment in Acts 2 to ALL the house of Israel. For the scripture saith:
Acts 2:36-38 KJV Therefore let all the house of Israel know assuredly, that God hath made the same Jesus, whom ye have crucified, both Lord and Christ. 37 Now when they heard this, they were pricked in their heart, and said unto Peter and to the rest of the apostles, Men and brethren, what shall we do? 38 Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost.
Acts 2:41 KJV Then they that gladly received his word were baptized: and the same day there were added unto them about three thousand souls.
They (all the house of Israel-every one of them) were to repent (change their mind) about WHO Jesus Christ was and be identified (water baptized) for the REMISSION of sins, and they would receive the gift of the Holy Ghost. NO MENTION "how that Christ died for our sins".
The gospel of Christ is the power of God unto salvation to every one that believeth! (Romans 1:16 KJV)
1 Corinthians 15:1-4 KJV Moreover, brethren, I declare unto you the gospel which I preached unto you, which also ye have received, and wherein ye stand; 2 By which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain. 3 For I delivered unto you first of all that which I also received, how 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:
And the fact that Jesus Christ died for YOURS and MY sins, aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world was UNSEARCHABLE!
Ephesians 2:11-12 KJV Wherefore remember, that ye being in time past Gentiles in the flesh, who are called Uncircumcision by that which is called the Circumcision in the flesh made by hands; 12 That at that time ye were without Christ, being aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world: 13 But now in Christ Jesus ye who sometimes were far off are made nigh by the blood of Christ.
2 Corinthians 5:19 KJV To wit, that God was in Christ, reconciling the world unto himself, not imputing their trespasses unto them; and hath committed unto us the word of reconciliation.
Ephesians 3:1 For this cause I Paul, the prisoner of Jesus Christ for you Gentiles, 2 If ye have heard of the dispensation of the grace of God which is given me to you-ward: 3 How that by revelation he made known unto me the mystery; (as I wrote afore in few words, 4 Whereby, when ye read, ye may understand my knowledge in the mystery of Christ) 5 Which in other ages was not made known unto the sons of men, as it is now revealed unto his holy apostles and prophets by the Spirit;
Ephesians 3:6 That the Gentiles should be fellowheirs, and of the same body, and partakers of his promise in Christ by the gospel: 7 Whereof I was made a minister, according to the gift of the grace of God given unto me by the effectual working of his power. 8 Unto me, who am less than the least of all saints, is this grace given, that I should preach among the Gentiles the unsearchable riches of Christ; 9 And to make all men see what is the fellowship of the mystery, which from the beginning of the world hath been hid in God, who created all things by Jesus Christ: 10 To the intent that now unto the principalities and powers in heavenly places might be known by the church the manifold wisdom of God, 11 According to the eternal purpose which he purposed in Christ Jesus our Lord: 12 In whom we have boldness and access with confidence by the faith of him.
This was all revealed TO and THROUGH the apostle Paul TO us by revelation of the risen, ascended, Lord Jesus Christ.