The biblical evidence of the pre-existence of the Son irrefutably proves the Oneness position false. Just as the present active participle huparchōn, in Philippians 2:6 communicates the perpetual existence of the divine Son, more than a few passages contain the present active participle ōn (from eimi), which also denotes the Son’s eternal existence (cf. Harris, 1992: 157-58). In explicit reference to the Son’s eternality, the present active participle is used both articularly (ho ōn) and anarthrously (ōn). Two such examples of the articular form of the participle are John 1:18 and Romans 9:5.
John 1:18: “No one has seen God at any time; the only begotten God who is [ho ōn, i.e., “the One who is/being always”] in the bosom of the Father, He has explained Him” (emphasis added).
Romans 9:5: “Whose are the fathers, and from whom is the Christ according to the flesh, who is [ho ōn, i.e., “the One who is/being always”] over all, God blessed forever. Amen” (emphasis added).
Note the defining context of both passages: the Son’s absolute deity. They even call the Son theos, which intensifies further the affirmation of the Son’s deity and His pre-existence. Referring to John 1:18, Reymond (1998: 303) remarks in the significance of the articular participle: “The present participle ho ōn … indicates a continuing state of being: ‘who is continually in the bosom of the Father.’” In the LXX of Exodus 3:14, we find the same articular present participle to denote Yahweh’s eternal existence: Egō eimi ho ōn, literally, “I am the eternal/always existing One.” Also note the egō eimi phrase preceding the participle here (cf. John 8:24, 58).
We also find the use of the anarthrous present active participle ōn, in contexts where the deity of the Son is clearly in view. In Hebrews 1:3, the present active anarthrous participle (i.e., hos ōn) also denotes the Son’s preexistence and total and full deity” (cf. Tenny, 1981: 34). It “refers to the absolute and timeless existence” (Rodgers and Rodgers, 1998: 516). The participle ōn in Hebrews 1:3 is set in contrast with genomenos, in verse 4. This is similar to the use of ēn, in John 1:1, which is set in contrast with egeneto, in 1:14, and of huparchōn, in Philippians 2:6 (cf. 2 Cor. 8:9), which is set in contrast with genomenos, in verse 7. In each case, there is an outstanding contrast between the eternal pre-incarnate Son and all things created.