In the history of Christianity there have been many ways to resolve the contradictions between Jesus being God, and Jesus being divine. In the centuries before the concept of the Trinity was invented, docetism was one belief professed by the very first Christians. It is the idea that Jesus was divine, but that to interact with the corrupt world was given the appearance of Humanity1,2. A lot of scripture supports this view. St Paul wrote that the Son came "in the likeness of flesh" (Romans 8:3). Joseph didn't impregnate Mary because Jesus didn't come from any physical seed. The reason Jesus didn't write anything himself or baptise anyone (John 4:1-2) is because he was a phantasm and could not. The evidence is that docetist Gospel of Peter was more widely read by the first Christians than Mark's3. Despite their early popularity, after the rise of Cappadocian and Pauline Christianity the docetists were forcibly silenced and mostly eradicated4.
“Docetism and its various branches held that Christ's human body was merely a phantom, and that his suffering and death were but appearance. If he suffered, he was not God, they argued, if he was God, he did not suffer: a most reasonable conclusion.”
“Docetists [...] maintained that since Christ was fully divine, he could not have been fully human and could not have really suffered (people suffer, God doesn't suffer). Why then did Christ 'seem' to be human? For docetists, it was all an appearance. Christ didn't have a real flesh-and-blood body and didn't really suffer and die. He only seemed to do so. [...]
Some docetists claimed that Christ's body only seemed to be human, because it was, in fact, phantasmal (like Casper the Friendly Ghost). The other docetic view is a bit more complicated. It maintained that there was a real man Jesus (flesh and blood like the rest of us), but there was also a different being known as the Christ. The Christ was a divine being who descended from heaven and came into Jesus at his baptism (the dove that descended on him and went into him), empowering him [... and] before Jesus died, the Christ left him to return to its heavenly home.”
The first belief amongst Christians was that of adoptionism, which is related to docetism. Some docetists had adoptionists beliefs: instead of Jesus always being a projection of God, at his baptism Jesus the human was endowed with Christ, the messiah. This is why no amazing stories exist of Jesus as an infant, teenager nor young adult. No cult of followers formed around him, and none of the Hebrew scribes mention him amongst their lists of magicians and wonder-workers. Jesus was a normal human; hence why the genealogies in the gospel trace his lineage to Joseph, his natural father. The spirit of God descended upon him in the form of a dove (Matthew 3:16, Mark 1:9-10 and Luke 3:22) which is why in John 1:32-34 God declares that he has (now) chosen Jesus. Because the Christ was eternal god and could not die, he departed from Jesus when he was hung on the cross. At that point, as recorded by Mark 15:34, Jesus cried out "My God, my God, why have you forsaken me?". Or literally translated "Why have you left me behind?"5.
The evidence is that The Gospel of Peter was more widely read by the first Christians than the Gospel of Mark6. It was known to be in use in Rhossus2, and a copy was discovered by archaeologists in 1886/7 near Akhmim in Egypt2. Later Christians declared it was heretical because it didn't agree with the new theology being developed by the Cappadocian/Nicene Christians in the 4th century; Eusebius writes about the Gospel of Peter in the 4th century and specifically argues against its docetist content in the 6th book of his Church History2.
The Gospel of Peter was docetist. In verses 10-20 it is specifically noted that Jesus hung on the cross silently "as if he had no pain" (verse 11)2 until the time that the Christ left him, at which point he cries out in verse 19: "My power, O power, you have left me"2 and is then "taken up", however, his body remains on the cross. In the now-found Gospel of Judas, Jesus would often be seen with completely different physical forms. "Often he did not appear to his disciples as himself, but he was found among them as a child" (33:19-20). [...] Jesus is able to change his appearance at will, according to this text - an idea found in a number of other early Christian writings [... including] the Acts of John". The Acts of John is a gnostic text, not from Nag Hammadi and in one story in it, one disciple sees Jesus as a child while at the same time another sees a cheerful man, and then as a man with a thick beard. From a docetist point of view, this makes sense, as the spirit of Christ is a phantom-like projection, so could of course appear however he wanted to appear7.
So how did modern Trinitarian Christianity begin? See: "How Modern Christianity Began: The Cappadocian-Nicene-Pauline Roman Amalgamation" by Vexen Crabtree (2008)
These early beliefs seem so at odds with modern Christian ideas about the Trinity, but, the Trinity simply hadn't been concocted yet. As Christianity emerged as a fusion of different historical religious styles and beliefs, there were growing arguments over exactly what form Jesus would have taken, or did take. The literalists didn't really understand docetism and portrayed it as 'strange', preferring instead the concept of the Trinity to overcome the fundamental contradictions between Jesus' divinity and humanity4. Neither strand answers all the problems. The phrase "Jesus incarnate" came about specifically so that non-docetist Christians could differentiate themselves from the docetist kind.
Docetism was popular enough amongst Christians that multiple authors and Church Fathers wrote arguments against them. The author of the Gospel of John specifically went out of its way to awkwardly state that "the Word became flesh, and dwelt among us" (John 1:1,14). Other anonymous letters and texts which accepted the Gospel of John were later named after John and the resulting literature called Johannine texts. 1 John 4:2-3 says that you can only be godly if you confess that Jesus was physical - docetists, says 1 John, are of the antichrist. Another Christian wrote against docetism in the name of John, and also said that docetists were ungodly. Despite being a forgery, the letter became known as the Second Epistle of John (2 John) and was also canonized in the New Testament, no doubt because the Cappadocian/Nicene Christians found it so useful to back up their belief in a physical fully-God and fully-Human Jesus.
Christian theologians Ignatius of Antioch (died between 98 and 117CE), Irenaeus (115-190CE), and Hippolatus (170-235CE) wrote against the error in the first few centuries8. Around 197-203CE the Bishop of Serapion of Antioch wrote against docetism after finding it in Rhosus, specifically, he wrote against the Gospel of Peter in a tract he titled "The So-Called Gospel of Peter" pointing out that although it was mostly correct, the Gospel of Peter could not be used because it supported docetism.9. St. Jerome (died 420CE) complained that "while the apostles were still surviving... the Lord's body was asserted to be but a phantasm"10. In 451CE, the great Christian Council of Chalcedon also condemned docetism8. Even though the orthodox hunted down and tried to eradicate heretics with increasing violence, the use of the Gospel of Peter continued until at least the 6th/7th century11 by which time the physical and literary dominance of Pauline / Nicene Christianity had become so great, it was getting very hard to imagine Jesus in any other way but theirs.
“The Second Epistle of John (2 John) is very short, just 13 verses. The author writes using the name of a well respected Christian in order to convince others that a particular belief is wrong. The entire epistle is about this one point. He writes against the belief that Jesus' body was spiritual in nature, and not fleshy; a belief known as docetism.”