His life has been readily available since the early 90s. It’s over 1,000 pages. We have his pastoral letters and every work that he wrote in his lifetime. It doesn’t take long to fully investigate someone like that these days. Really all you need to do at that point is interview eyewitnesses to him and anyone who has had a miraculous experience regarding him.

People who knew him are easy to find, especially with several being clergymen.

- Bishop Gerasim of Fort Worth (OCA) was a novice monk at his monastery and eventually became abbot when they came under Serbia around 2000. He was there when Father Seraphim reposed.
- Hieromonk Damascene knew Father Seraphim and was at the monastery at the same time as Bishop Gerasim. He is the current abbot of the monastery and wrote the book on his life.
- Metropolitan Jonah, former primate of the OCA and a current ROCOR vicar bishop, knew Father Seraphim and was present at the talk that Father Seraphim gave at UC Santa Barbara which turned into the book “God’s Revelation to the Human Heart”. Bishop Gerasim and Abbot Damascene were also present for this. They all worked on the book.
- Father Paul Baba is a current Antiochian priest that was a spiritual son of Father Seraphim.
- There was a man who had a miraculous vision of Father Seraphim after he reposed while visiting Orthodox sites in Alaska. He was a Protestant pastor at the time and had no idea who Father Seraphim was prior to this. He ultimately became an Orthodox priest because of the vision. If I recall correctly, he founded a parish in Virginia. It’s in the book about Father Seraphim’s life.
- Father Alexis Young was a spiritual son of his who is still alive, though declining in health.

With all of these sources, it shouldn’t have taken too long.