>This doesn't prove he doesn't exist or anything, but it's really strange. Here is this guy performing miracles, saying he's the son of god, but there is nothing till 30-100 years after his death.
It might be better to ask, Why were the Gospels written at all? If we think in categories of delay, then this presupposes that the writing of the Gospels was in the minds of these authors from the beginning. However, that is almost certainly not the case. What was paramount in the apostles' earliest motives was oral proclamation of the gospel. They wanted to disseminate the word as quickly as possible. And writing it down by hand and making copies takes a lot of time.
In other words, the apostles and leaders of the young church were preoccupied with broadcasting the gospel orally. There was no need to think about a written gospel at this time. The remarkable speed with which the good news of Jesus Christ became known throughout the Roman Empire in the first few years of the church's existence is testimony to the apostles' success in the task of oral proclamation.
Scholars often point to two catalysts that prompted the writing of the Gospels. First, the apostles started to die off. And second, the Lord's return was evidently not going to happen within the first few decades of the church's existence. These two factors are often suggested gested as the main reasons why the Gospels began to be written. source
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