Our term "manifestation" is based on the King James Version of
1 Timothy 3:16 which says:
And without controversy great is the mystery of godliness: God was manifest in the flesh...
KJV
Here are some other translations/version of that passage:
--Beyond all question, the mystery of godliness is great:
He[a] appeared in a body,[b]...
Footnotes:
1.
1 Timothy 3:16 Some manuscripts God
2.
1 Timothy 3:16 Or in the flesh
(NIV)
--By common confession, great is the mystery of godliness:
He who was revealed in the flesh,...
(NASB)
--This Christian life is a great mystery, far exceeding our understanding, but some things are clear enough:
He appeared in a human body, ...
(The Message)
--And great and important and weighty, we confess, is the hidden truth (the mystic secret) of godliness. He [[a]God] was made visible in human flesh,...
Footnotes:
1.
1 Timothy 3:16 Some manuscripts read "God."
(Amplified Bible)
--Without question, this is the great mystery of our faith:
Christ was revealed in a human body...
(NLT)
--Great indeed, we confess, is the mystery of godliness:
He[a] was manifested in the flesh,
Footnotes:
1.
1 Timothy 3:16 Greek Who; some manuscripts God; others Which
(ESV)
--And without controversy great is the mystery of godliness:
God[a] was manifested in the flesh,...
Footnotes:
1.
1 Timothy 3:16 NU-Text reads Who
(NKVV)
--confessedly, great is the secret of piety -- God was manifested in flesh
(YLT)
--And great beyond all question is the mystery of our religion:
He who was manifested in the body...
(NEB)
--And without controversy, great is the mystery of godliness, which is, God is manifested in the flesh..."
(1599 Geneva Bible)
--Without any doubt, the mystery of our religion is great:
He was revealed in flesh,...
(NRSV)
--Great beyond all question is the formerly hidden truth underlying our faith:
He was manifested physically...
(CJB)
--And confessedly great is the mystery of the piety; God made manifest in flesh...
(Apostolic Bible Polyglott)
So, based on these versions, "God" or "He" or "He Who" or "Christ" was
"manifest in the flesh"
"revealed in flesh"
"manifested physically"
"made manifest in flesh"
"manifested in flesh"
"manifested in the body"
The Apostolic Bible Polyglott is a Greek/English interlinear Bible with the Strong's numbers shown for each word. According to that version which uses the term "made manifest" it is the word no. 5319, phaneroo, which means or is translated "to make manifest, or known; to make apparent; to declare."
In my Strong's concordance it says the word means or is translated ""appear, manifestly declare, (make) manifest (forth), shew (self)"