soft sf whereas Blish and Anderson were American agnostics and professional writers of hard sf. Some of Blish's works are "post-Lewis."
Theological conviction was the primary motivation of Lewis' fiction whereas Blish and Anderson addressed every important issue, including theology. Blish has Believers in Volume I of Cities In Flight, Warriors of God in Volume IV and similar characters or situations in other works. The volumes of his After Such Knowledge Trilogy are respectively historical fiction, contemporary fantasy and futuristic sf. Volumes II and III acknowledge Lewis. Volume II treats angels and demons as real beings and describes a change in the supernatural realm.
Poul and Karen Anderson's The King Of Ys Tetralogy combines historical fiction with fantasy, treats gods as real beings and describes changes in the supernatural realm. Maybe After Such Knowledge and The King Of Ys have more in common than I previously thought.