Below comes from my computer Bible program, specifically the 'New Testament verse references in the Ante-Nicene Fathers.
1Jn 4:1
Irenaeus Against Heresies Book III
ccel.org/fathers2/ANF-01/anf01-60.htm#P7661_2081885
Hereby know ye the Spirit of God: Every spirit that confesseth that Jesus Christ is come in the flesh is of God; and every spirit which separates Jesus Christ is not of God, but is of antichrist."[297]
Tertullian Against Marcion Book V
ccel.org/fathers2/ANF-03/anf03-35.htm#P7919_2255849
by the Apostle John, who says that “already many false prophets are gone out into the world,” the fore-runners of Antichrist, who deny that Christ is come in the flesh,[740]
Dubious Hippolytus Fragments
ccel.org/fathers2/ANF-05/anf05-20.htm
Believe not every spirit, because many false prophets are gone out into the world."[37]
1Jn 4:2
Tertullian Against Praxeas
ccel.org/fathers2/ANF-03/anf03-43.htm#P10855_3047505
John, moreover, brands that man as “a liar” who "denieth that Jesus is the Christ; "whilst on the other hand he declares that “every one is born of God who believeth that Jesus is the Christ.”[398]
Cyprian Treatise XII Three Books of Testimonies Against the Jews
ccel.org/fathers2/ANF-05/anf05-122.htm#P8139_2700937
But whosoever denies that He is come in the flesh is not of God, but is of the spirit of Antichrist."[184]
1Jn 4:3
Epistle of Polycarp to the Philippians
ccel.org/fathers2/ANF-01/anf01-11.htm#P832_153920
"For whosoever does not confess that Jesus Christ has come in the flesh, is antichrist; "[41]
Epistle of Ignatius to the Antiochians
ccel.org/fathers2/ANF-01/anf01-29.htm#P2721_444612
And he that rejects the incarnation, and is ashamed of the cross for which I am in bonds, this man is antichrist.[24]
Tertullian The Prescription Against Heretics
ccel.org/fathers2/ANF-03/anf03-24.htm#P3568_1214235
But in his epistle he especially designates those as “Antichrists” who “denied that Christ was come in the flesh,”[361]
Tertullian Against Marcion Book V
ccel.org/fathers2/ANF-03/anf03-35.htm#P7919_2255849
and do not acknowledge[741]
Tertullian On the Flesh of Christ
ccel.org/fathers2/ANF-03/anf03-39.htm#P9641_2643799
the virgin friend of Apelles. Surely he is antichrist who denies that Christ has come in the flesh.[339]
Tertullian On the Resurrection of the Flesh
ccel.org/fathers2/ANF-03/anf03-41.htm#P9872_2728142
no one has as yet escaped from Antichrist;[144]
Cyprian Epistle LXXII
ccel.org/fathers2/ANF-05/anf05-97.htm#P6270_1984260
how can either darkness illuminate, or unrighteousness justify? And when they say that “they are not of God, but are of the spirit of Antichrist,”[20]
1Jn 4:4
Cyprian Epistle VIII
ccel.org/fathers2/ANF-05/anf05-33.htm#P4898_1482943
re already crowned, while some are even now within reach of the crown of victory; but all whom the danger has shut up in a glorious company are animated to carry on the struggle with an equal and common warmth of virtue, as it behoves the soldiers of Christ in the divine camp: that no allurements may deceive the incorruptible stedfastness of your faith, no threats terrify you, no sufferings or tortures overcome you, because "greater is He that is in us, than he that is in the world; "[2]
Cyprian Treatise XI Exhortation to Martyrdom Addressed to Fortunatus
ccel.org/fathers2/ANF-05/anf05-121.htm#P7766_2610984
John, in his epistle, proves this, saying: “Greater is He who is in you than he that is in the world.”[70]
Cyprian Treatise XII Three Books of Testimonies Against the Jews
ccel.org/fathers2/ANF-05/anf05-122.htm#P8544_2777276
Of this thing also in John: “Greater is He who is in you than he who is in this world.”[430]
1Jn 4:6
Shepherd of Hermas Commandment Third
ccel.org/fathers2/ANF-02/anf02-13.htm
How then can I live, since I have acted thus? "And he said to me, “Your feelings are indeed right and sound, for you ought as a servant of God to have walked in truth, and not to have joined an evil conscience with the spirit of truth, nor to have caused sadness to the holy and true Spirit.”[5]