Christian books about escaping from Soviet Union: Read late 1970s

[Karyn]

I read a series (3?4?) books about the persecution of Christians in and theirs escapes from Soviet Russia, but can’t remember much more. They were unapologetically pro-Christian, anti-Soviet propaganda posing as pseudo-real-life stories.

[Rainbowheart]

The Ivan series by Myrna Grant?

I believe Ivan and the Hidden Bible is the first book.