Macbeth and the Culdees
The Ceil-De, ‘servants of God, or Culdees as they are known, were an ascetic, reformist monastic movement whose members believed that society’s moral failings had been punished by the arrival of the Vikings. Even in the 11th century, then people were seeking a return to ‘traditional’ values!
St. Serfs on Loch Leven
One such Culdee community was on the island of St Serfs in Loch Leven and this small monastic community had become an important religious and academic centre by the early 11th century with monks employed copying manuscripts. Whether for religious or other reasons, Macbeth and his wife Gruoch granted land to the Culdees of St. Serfs.Grants of land of this kind were common. Some people have seen Macbeth's grant-giving as an attempt to assuage feelings of guilt he felt at the 'murder' of King Duncan, but it is more likely that Macbeth and Gruoch are simply following established practice by granting land to the church.
Meanwhile, back in Moray..
Loch Leven, of course, is in Perth and Kinross Perthshire, not Moray, but there are no surviving records of Macbeth granting lands to the church in his home province. It would be surprising if he didn't do so, however, and he very probably used churchmen as administrators and clerics in his own household.
Loch Leven St Serfs

Abbey ruins at Culcross