This is patently untrue. Do your research.

At least seventeen non-Christian writings dated between twenty and 150 years after Jesus’ death record over fifty details concerning Jesus’ life, teachings, death, and resurrection.

Now, you might think that seventeen non-Biblical sources is hardly compelling. However, we are talking about a time in history where it wasn’t exactly straightforward to write things down. That aside, if you compare the seventeen sources that talk about Jesus with other historical figures that we all assume existed, Jesus certainly stacks up well.

For example, there are only five surviving accounts of Alexander the Great — none of them primary sources.