He can't afford to make mistakes. Nor can he allow Alfin to make some for him. If the word of Alfin's prophetic powers were to be leaked, a disaster will strike Riber city. Not to mention if these magicians came to believe in Alfin's reincarnation story, Wilkis didn't know if he would be able to handle the aftermath.
The story, Alfin told him was just too great and the ramifications of it being true were too dangerous and hopeless.
For the first time in his life, Wilkis has chosen to keep his curiosity in check, he didn't wish to confirm whether Alfin's words are true or not, he needs to live in the present and maintain the status quo of the current world and save his people.
This meant that no matter what happens, he can't allow Radeka to meet Alfin.