So my advice is to learn about manuscripts.
John 5:4
https://www.biblegateway.com/passage/?search=John+5:4&version=NIV
https://www.jw.org/en/library/bible/study-bible/books/john/5/#v43005004
The words do not occur in the following corrupted texts:
P66, P75, Aleph (Sinaiticus), B (Vaticanus), C*, D, W-suppl, 0125, 0141, pc, d, flg, Vulgate-pt, Curetonian, Bohairic-pt, ach2, Armenian-mss
Here is the vast extant literature which has the text in it:
"... A,C-3, E, F, G, H, K, L, M, (S*), U, V, X-comm
Gamma, Delta, Theta, Lambda, Psi
047, 063, 078
Cursives: MAJORITY, fam 1,13
Old Latin: a, aur, b, c, e, ff2, g1, , j, r1, Vulgate
Syriac: Pes.hitta, Harclean, Palestinian
Coptic: Bohairic-pt
Armenian, Ethiopic
Also extant in Y, Omega, 055, 0211, 0233? ...
Tertullian (c. 200) refers to the passage and Tatian (c. 175) placed it in his Diatessaron. ..." - A Closer Look: Early Manuscripts & The A.V.; by Jack Moorman, page 102
Additionally:
"... TAITIAN, Diatessaron (I 10:77)
TERTULLIAN, Baptism (I 3:671,672)
GREGORY OF NAZIANZEN, Orations (III 7:372)
AMBROSE, Mysteries (III 10:320)
The index of the ANPF do not show any pre-400 AD Father quoting John 5:2,5 with the disputed portion omitted. There are no references to 5:2. There are four references in the Ante-Nicene volumes to 5:5. These are 1:393, 6:395, 8:419,428. ..." - Early Church Fathers and the Authorized Verson, by Jack Moorman, page 48
Additionally:
"... Verse 4 is found (with variations) in uncials A, C3, K, L, Pi, X comm, Delta, Theta, Psi, 047, 063, 078, cursives 28, 565, 700, 892, 1009, 1010, 1071, 1079, 1195, 1216, 1230, 1241, 1242, 1253, 1344, 1365, 1546, 1646,2148, 2174, Byzantine majority text and Lectionaries, Old Latin a (4th c), aur (7th), b (5th), c (12/13th), e (5th), f12 (5th),j (6th), rl (7th), the Syriac (Harkelian, Peshitta, Philoxenian, 3rd- 7th c), some manuscripts of the Coptic-Bohairic, the Armenian version; Diatessaron a, e arm, 1, n; Tertullian (220 AD), Ambrose (397 AD), Didymus (398 AD), Chrysostom (407 AD), Cyril (444 AD).
Ruckman (2) p 217, states that the Diatessaron copies (2nd century) attesting to the passage number over 200. Ruckman, ibid and Hills (3) p 146, (38) p 122, state that the passage is virtually intact in the vast majority of Greek manuscripts. See Fuller (33) p 157-8. Berry's Greek text supports this passage. ..." - http://ecclesia.org/truth/manuscript_evidence.html
Additionally:
"... Even the recent Nestle-Aland 27th edition critical text acknowledges that verse four is found in the Majority of all Greek manuscripts, the Old Latin, the Vulgate Clementine, the Syriac Peshitta and Harkelian, and in some copies of the Coptic Boharic ancient versions.
As for Robertson’s codex C, it was amended to now agree with the reading found in the King James Bible, and the codex D he mentions retains the words Robertson would have us omit from verse three. Robertson’s “oldest and best manuscripts” can’t even agree among themselves. ..." - https://brandplucked.webs.com/john534troubling.htm