to the praise of the glory of his favor, by which he favored on us in the Beloved,
to the praise of the glory of his favor by which he showed favor to us - Glory and riches were expected to come to some Jews when the Messiah would come in the Day of Destruction. Paul changes this expectation by praising the glory of God's favor (Paul will address riches in Eph. 1:7). God's favor would not bring glory and riches but rather, glory and riches is His favor itself!
- Ephesians 1:6
in the Beloved - False teachers were saying that Jesus was not loved by God. Paul responds to this by calling Jesus "Beloved". Gospel writers make it a point to show that Jesus was loved by God:
A voice came out of the sky, "You are my beloved Son, in whom I am well pleased." See also Mat. 3:17, 12:18, 17:5, Mark 9:7, Luk. 3:22