You claimed that Constantine made Christianity "the" State religion in 324. He did no such thing.
I'm not the one making false claims.
Wars against Licinius
In the following years, Constantine gradually consolidated his military superiority over his rivals in the crumbling Tetrarchy. In 313, he met
Licinius in
Milan to secure their alliance by the marriage of Licinius and Constantine's half-sister
Constantia. During this meeting, the emperors agreed on the so-called
Edict of Milan,
[195] officially granting full tolerance to Christianity and all religions in the Empire.
[196] The document had special benefits for Christians, legalizing their religion and granting them restoration for all property seized during Diocletian's persecution. It repudiates past methods of religious coercion and used only general terms to refer to the divine sphere—"Divinity" and "Supreme Divinity",
summa divinitas.
[197] The conference was cut short, however, when news reached Licinius that his rival
Maximinus had crossed the
Bosporus and invaded European territory. Licinius departed and eventually defeated Maximinus, gaining control over the entire eastern half of the Roman Empire. Relations between the two remaining emperors deteriorated, as Constantine suffered an assassination attempt at the hands of a character that Licinius wanted elevated to the rank of Caesar;
[198] Licinius, for his part, had Constantine's statues in Emona destroyed.
[199] In either 314 or 316 AD, the two Augusti fought against one another at the
Battle of Cibalae, with Constantine being victorious. They clashed again at the
Battle of Mardia in 317, and agreed to a settlement in which Constantine's sons
Crispus and
Constantine II, and Licinius' son Licinianus were made
caesars.
[200] After this arrangement, Constantine ruled the dioceses of Pannonia and Macedonia and took residence at
Sirmium, whence he could wage war on the Goths and Sarmatians in 322, and on the Goths in 323, defeating and killing their leader
Rausimod.
[198]
In the year 320, Licinius allegedly reneged on the religious freedom promised by the Edict of Milan in 313 and began to oppress Christians anew,
[201] generally without bloodshed, but resorting to confiscations and sacking of Christian office-holders.
[202] Although this characterization of Licinius as anti-Christian is somewhat doubtful, the fact is that he seems to have been far less open in his support of Christianity than Constantine. Therefore, Licinius was prone to see the Church as a force more loyal to Constantine than to the Imperial system in general,
[203] as the explanation offered by the Church historian
Sozomen.
[204]
This dubious arrangement eventually became a challenge to Constantine in the West, climaxing in the great civil war of 324. Licinius, aided by
Goths mercenaries, represented the past and the ancient
pagan faiths. Constantine and his
Franks marched under the standard of the
labarum, and both sides saw the battle in religious terms. Outnumbered, but fired by their zeal, Constantine's army emerged victorious in the
Battle of Adrianople. Licinius fled across the Bosphorus and appointed
Martinian, his
magister officiorum, as nominal Augustus in the West, but Constantine next won the
Battle of the Hellespont, and finally the
Battle of Chrysopolis on 18 September 324.
[205] Licinius and Martinian surrendered to Constantine at Nicomedia on the promise their lives would be spared: they were sent to live as private citizens in Thessalonica and Cappadocia respectively, but in 325 Constantine accused Licinius of plotting against him and had them both arrested and hanged; Licinius' son (the son of Constantine's half-sister) was killed in 326.
[206] Thus Constantine became the sole emperor of the Roman Empire.
[2
In 321, he legislated that the
venerable Sunday should be a day of rest for all citizens.
[224] In 323, he issued a decree banning Christians from participating in state sacrifices.
[225] After the pagan gods had disappeared from his coinage, Christian symbols appeared as Constantine's attributes, the chi rho between his hands or on his
labarum,
[226] as well on the coin itself.
[227]
The reign of Constantine established a precedent for the emperor to have great influence and authority in the early Christian councils, most notably the dispute over
Arianism. Constantine disliked the risks to societal stability that religious disputes and controversies brought with them, preferring to establish an orthodoxy.
[228] His influence over the Church councils was to enforce doctrine, root out heresy, and uphold ecclesiastical unity; the Church's role was to determine proper worship, doctrines, and dogma.
[229]
Source Wikipedia
Looks like establishing Christianity to me. BTW - I am not SDA.