Question: What happened to Lazarus after he was raised from the dead (John 11:43-44)?
Answer: When Lazarus was brought back from the dead, he was restored to life but didn't receive a glorified resurrection body. Since Jesus was the first fruits from the dead (1 Cor. 15:20), He was the first to receive a glorified resurrection body. Therefore, Lazarus was raised in his natural body, which died again some time after he was raised.
We don't hear any more about Lazarus after he was raised because there wasn't anything noteworthy that needed to be recorded. The focus of the gospels is on the life of Christ, and Jesus did many things which weren't recorded. "And there are also many other things which Jesus did, which if they were written in detail, I suppose that even the world itself would not contain the books which were written" (John 21:25).
blue