Isaiah 45 is perhaps one of the most monotheistic text. For example, consider these almost verbatim repetitions in the passage:
“…I am the LORD, and there is no other, besides me there is no God…” (v. 5)
“…I am the LORD, and there is no other…” (v. 6)
“…’Surely God is in you, and there is no other, no god besides him’…” (v.14)
“…I am the LORD, and there is no other…” (v. 18)
“…And there is no other god besides me, a righteous God and a Savior; there is none besides me…” (v. 21)
“…For I am God; there is none besides me…” (v. 22)
Yet, St. Paul used this text precisely when he said that “at the name of Jesus every knee should bow, in heaven and on earth and under the earth, and every tongue confess that Jesus Christ is Lord” (Phi 2.10-11), thereby echoing Isa 45.23, “to me every knee shall bow, every tongue shall swear allegiance”, which was originally meant only and only for YHWH (cf. his other usage at Rm 14.11); i.e., he deliberately identified Jesus with YHWH.