Any gospel which is NOT the true Gospel of God is ultimately from Satan (who belongs to the pit of Hell, since Hell was created for the devil and his angels).
It is extremely unfortunate that Reformed Theology came up with ANOTHER GOSPEL (when the Reformers had every reason to have the true Gospel). And here is the evidence from the Westminster Confession of Faith. Every Calvinist must subscribe to this in order to call himself or herself a Reformed Christian.
WESTMINSTER CONFESSION OF FAITH
CHAPTER III Of God's Eternal Decree
III. By the decree of God, for the manifestation of His glory, some men and angels 70 are predestinated unto everlasting life; and others foreordained to everlasting death.71 IV. These angels and men, thus predestinated, and foreordained, are particularly and unchangeably designed, and their number so certain and definite, that it cannot be either increased or diminished.72
VII. The rest of mankind God was pleased, according to the unsearchable counsel of His own will, whereby He extends or withholds mercy, as He pleases, for the glory of His sovereign power over His creatures, to pass by; and to ordain them to dishonor and wrath for their sin, to the praised of His glorious justice. 80
What are these two sections teaching? That some men are PREDESTINED to receive eternal life and "the rest of mankind" is created for eternal damnation ("everlasting death"). And if that is not from the pit of Hell, then you really do not understand the Gospel.
Jesus, the apostles, and the Bible itself TOTALLY REFUTES this garbage. Here are just a few Scriptures which reveal that God offers salvation to all mankind.
Look unto me, and be ye saved, all the ends of the earth: for I am God, and there is none else. (Isa 45:22)
Ho, every one that thirsteth, come ye to the waters, and he that hath no money; come ye, buy, and eat; yea, come, buy wine and milk without money and without price. (Isa 55:1)
And He [CHRIST] said unto them, Go ye into all the world, and preach the Gospel to every creature. He that believeth and is baptized shall be saved; but he that believeth not shall be damned. (Mk 16:15,16)
And I, if I be lifted up from the earth, will draw all men unto me. This he said, signifying what death he should die. (Jn 12:32)
For this is good and acceptable in the sight of God our Saviour; Who will have all men to be saved, and to come unto the knowledge of the truth. For there is one God, and one mediator between God and men, the man Christ Jesus; Who gave himself a ransom for all, to be testified in due time. (1 Tim 2:3-6)
But we see Jesus, who was made a little lower than the angels for the suffering of death, crowned with glory and honour; that he by the grace of God should taste death for every man. (Heb 2:9)
The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance. (2 Pet 3:9)
And the Spirit and the bride say, Come. And let him that heareth say, Come. And let him that is athirst come. And whosoever will, let him take the water of life freely. (Rev 22:17)