Of course they are to the Jews, but which is not a different gospel than to the Gentiles, but of salvation by faith, a faith which is (normally) confessed in baptism.
The error of the Judaizers was in keeping the whole law and as if this system of merit saved them, plus belief in the Lord Jesus, versus being justified by faith in Him to save on His expense and righteousness, but which faith is manifest in following Him, (Jn. 10:27,28) constituting the "obedience of faith" which works towards practically fulfilling the holy intent of the Law. (Acts 8:4) And which faith God blesses in grace. (Heb. 10:35)
Not only that, baptism for the remission of sins is preached, repentance unto salvation is preached. Everything is preached unto these people except ONE THING: the salvation by grace through faith. Not ONCE do we read that Christ DIED for our sins, was buried, and rose the third day, mentioned.
That is simply erroneous and you have not understood what i wrote. There is not two gospels, but one in which, as Paul stated, was that of
Testifying both to the Jews , and also to the Greeks , repentance toward God, and faith toward our Lord Jesus Christ. (Acts 20:21)
...shewed first unto them of Damascus, and at Jerusalem , and throughout all the coasts of Judæa, and then to the Gentiles , that they should repent and turn to God, and do works meet for repentance. (Acts 26:20)
Both Jews and Gentiles are called to repentant faith, as repentance and faith go together, two sides of the same coin, for you cannot believe on the Lord Jesus who died for our sins without it effecting obedience to them. In Acts 2:14-40 Peter explicitly preached that
And it shall come to pass, that whosoever shall call on the name of the Lord shall be saved. (Acts 2:21) going on to explain how the death, burial and resurrection of the sinless Lord Jesus was a fulfillment of prophecy, like as he told the Gentiles,
To him give all the prophets witness, that through his name whosoever believeth in him shall receive remission of sins. (Acts 10:43; cf. Joel 2:32)
Having convicted them of sin (they killed their righteousness Savior), and of righteousness (God raised Him up because He was) , and of judgment (that the Lord Jesus was going to make them His footstool), they cried out asking how they could be saved. And Peter's reply is a call to repentant faith, which is confessed in baptism.
You can object that this is calling man to do a work, to make a response, but unless you believe souls are saved in their sleep, then you do the same in calling them to respond to the gospel. Peter here was simply telling them to call upon the Lord Jesus, as he had prior said they would be saved by, by confessing Him in baptism.
And which again is consistent with Paul,
For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation. (Romans 10:10)
As said, there is no real difference btwn moving your tongue in confessing the risen Lord and Savior, versus confessing that in body language. Even moving neurons in your brain in believing is a response man chooses to do so by grace, without which he could not and would not. (But election is made before man can do anything: Rm. 11:16) Certainly souls are not converted while comatose, but when they believe.
If some asks me what they must do to be saved, i can tell them to That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved. (Romans 10:9) But telling them to be baptized in His name, if understood as being a proper confession of the Lord Jesus (not that the act saves them) then i am doing the same thing. That is their "altar call " or salvation.
Thus Paul baptized as being synonymous with believing.
Then said Paul, John verily baptized with the baptism of repentance, saying unto the people, that they should believe on him which should come after him, that is, on Christ Jesus. When they heard this, they were baptized in the name of the Lord Jesus. (Acts 19:4-5)
This was done as part of fulfilling the Great Commission which was for the whole world.
Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: (Matthew 28:19)
While it is repentant faith in the heart that is imputed unto righteousness, even before it is manifestly confessed, yet the time of this confession can be the time when they first truly believe, which faith God grants to helpless man, and which faith He blesses. Conversely, some souls were never saved because they would not heed the altar call for salvation.
And as saving faith is a repentant faith, thus as said, Paul stated
For not the hearers of the law are just before God, but the doers of the law shall be justified. (Romans 2:13)
Not because their holy works in fulfilling the righteous intent of the law earn them salvation, but because this is evidence of faith in the Lord Jesus, the faith which justifies.
Therefore Scripture is consistent with itself as concerns the gospel of grace, as there is not two gospels, which would render Peter being accused, (Gal. 1:6-9) but both Peter and Paul preached the same gospel, both to the Jews, and also to the Greeks, repentance toward God, and faith toward our Lord Jesus Christ. (Acts 20:21)
And so must we.
Faith exhibited by works? What was the “gospel of grace” which Paul said had been a “mystery” until after Pentecost? That gospel could not have been preached prior.
“Peter here was simply telling them to call upon the Lord Jesus, as he had prior said they would be saved by, by confessing Him in baptism.”
Then you claimed this was consistent with that.
“For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation. (Romans 10:10)”
In the first case Peter said “confessing Him in baptism”. In the second Paul said “with the mouth confession is made unto salvation”.
Do you really see those two as consistent?