The actual definition of a Christian is someone who believes that Jesus is the Christ (aka the Son of God and God the Son.)

Assuming there is an ultimate truth out there (and it's truly terrifying if there isn't), and assuming Jesus is that said Christ, then true Christians are, indeed, people of the truth. As in, they belong to the source of truth. It doesn't mean they are by any means perfect or even truthful, but hopefully, are doing their best to pursue the truth to which they belong.

The Bible says humans can't actually fully grasp the truth. It says we're all "seeing dimly, as in a foggy mirror." That's about as clear a description of humanity as I've ever seen!