The gnostics explained existence as beginning at the lowest, evil level of matter and proceeding upward through emanations towards God who is spirit and good and inhabits the highest, heavenly sphere. If you followed these teachers it would undermine what the Bible says about God. At creation God said, "'Let Us make man in Our image'" (Ge 1:26; 3:22; 11:7). The name is Elohim which represents the triune God. Firstly, "the Spirit of God was moving over the surface of the waters" (1:2), and furthermore, Paul uses the greeting in his letters of, "Grace to you and peace from God our Father and the Lord Jesus Christ" (Ro 1:7; 1Co 1:3; Gal 1:3). The gnostics said that YHWH created the universe which is composed of matter so he would have to be a lower emanation because he identified with matter. However, YHWH is composed of the four consonants which make up the divine name (i.e. the Hebrew language doesn't include vowels so the readers supply them when they read). Then they decided to be extra-careful not to misuse God's name because, "'You shall not take the name of the Lord your God in vain, for the Lord will not leave him unpunished who takes His name in vain" (Ex 20:7). To protect against mistakes the scribes put the vowels from "Adonai" (Lord) beside the consonants to remind them to say Lord instead. Then a Latinized form pronounced Jehovah was created from it which was actually not a real word at all. The real pronunciation of YHWH was lost over time but scholars believe it was probably pronounced Yahweh. Moses asked God who he should say sent him and God replied, "'I am who I am'" (Ex 3:14). Also, God said to say to Israel that he was "'The Lord, the God of your fathers'" (:15). "'This is My name forever, and this is My memorial-name to all generations'" (:15). "Even the Lord, the God of hosts, the Lord is His name" (Hos 12:5).
The gnostics had differing interpretations of who Jesus was. Some said he was equal with God so others then pointed out that he couldn't therefore have appeared in a human body. Then others countered that he just seemed human but was really spirit. However, if he was not incarnate then his sacrifice would have been in vain. Also, if he was not completely divine then he wouldn't have qualified as being sinless. "Although He existed in the form of God, [he] did not regard equality with God a thing to be grasped, but emptied Himself, taking the form of a bond-servant . . . [and] humbled Himself by becoming obedient to the point of death" (Php 2:6-8). After he was resurrected he identified himself to John as "'the Alpha and Omega . . . who is and who was and who is to come, the Almighty'" (Rev 1:8) and again as "'the first and the last, who was dead and has come to life'" (2:8). In addition, "He is the image of the invisible God" (Col 1:15). "He is the radiance of His glory and the exact representation of His nature" (Heb 1:3). "In Him all the fulness of Deity dwells in bodily form" (Col 2:9). Jesus told Philip, "'He who has seen Me has seen the Father'" (Jn 14:9). "'From now on you know Him, and have seen Him'" (:17).