The Gospel Impossible to save is any gospel of salvation by anything other than faith only.
Not according to the NT where we are in the new covenant
and under the law of Christ (Mt 22:37-39)
(without all the myriad regulations of the law of Moses),
as spoken by the Son in these last days (Heb 1:1-2)
through the NT writers in the commands and exhortations of the NT.
"Faith only"
Faith to know Y'shua came to save the lost sheep of the House of Israel by being both God and man, by dying and resurrecting so that His people could be brought back into the Kingdom of God.
Rom 7:1 Know ye not, brethren, (for I speak to them that know the law,) how that the law hath dominion over a man as long as he liveth?
Rom 7:2 For the woman which hath an husband is bound by the law to her husband so long as he liveth; but if the husband be dead, she is loosed from the law of her husband.
Rom 7:3 So then if, while her husband liveth, she be married to another man, she shall be called an adulteress: but if her husband be dead, she is free from that law; so that she is no adulteress, though she be married to another man.
Rom 7:4 Wherefore, my brethren, ye also are become dead to the law by the body of Christ; that ye should be married to another, even to him who is raised from the dead, that we should bring forth fruit unto God.
Rom 7:5 For when we were in the flesh, the motions of sins, which were by the law, did work in our members to bring forth fruit unto death.
Rom 7:6 But now we are delivered from the law, that being dead wherein we were held; that we should serve in newness of spirit, and not in the oldness of the letter.
AND THAT "LAW" THAT IS BEING SPOKEN OF:
Deu 24:1 When a man hath taken a wife, and married her, and it come to pass that she find no favour in his eyes, because he hath found some uncleanness in her: then let him write her a bill of divorcement, and give it in her hand, and send her out of his house.
Deu 24:2 And when she is departed out of his house, she may go and be another man's wife.
Deu 24:3 And if the latter husband hate her, and write her a bill of divorcement, and giveth it in her hand, and sendeth her out of his house; or if the latter husband die, which took her to be his wife;
Deu 24:4 Her former husband, which sent her away, may not take her again to be his wife, after that she is defiled; for that is abomination before the LORD: and thou shalt not cause the land to sin, which the LORD thy God giveth thee for an inheritance
What is the New Covenant?
Jer 31:33 But this shall be the covenant that I will make with the house of Israel; After those days, saith the LORD, I will put my law in their inward parts, and write it in their hearts; and will be their God, and they shall be my people.
Jer 31:34 And they shall teach no more every man his neighbour, and every man his brother, saying, Know the LORD: for they shall all know me, from the least of them unto the greatest of them, saith the LORD: for I will forgive their iniquity, and I will remember their sin no more.
Mat_10:6 But go rather to the lost sheep of the house of Israel.
Mat_15:24 But he answered and said, I am not sent but unto the lost sheep of the house of Israel.
Heb 8:8 For finding fault with them, he saith, Behold, the days come, saith the Lord, when I will make a new covenant with the house of Israel and with the house of Judah:
Heb 8:9 Not according to the covenant that I made with their fathers in the day when I took them by the hand to lead them out of the land of Egypt; because they continued not in my covenant, and I regarded them not, saith the Lord.
Heb 8:10 For this is the covenant that I will make with the house of Israel after those days, saith the Lord; I will put my laws into their mind, and write them in their hearts: and I will be to them a God, and they shall be to me a people:
So those who know the law (as Paul stated) will understand the law of marriage, divorce and remarry.
Will God remarry the House of Israel? Absolutely yes!! This is the great mystery Paul brought to the "gentiles" who are of the House of Israel and through Paul's letters is still reaching the lost sheep of the House of Israel and also to any who want to join Israel and keep the commandments (which is how we are known to be of YHWH, which God is ours).
Do you have failth only that says you are saved and now you desire to bring forth good fruit, as defined by scripture, good fruit is living, keeping, guarding our Husbands "laws" of His household? Y'shua's gospel is not just about Himself, but about His Kingdom and those who will be in the Kingdom and those who will not be in the Kingdom.