Loic does start off in the chapel, but should stick around until you are ready to do the trial. Is he not at the end?
See
here or
here for a couple walkthroughs of that section.
If you still can not find him, and are playing on PC, you can email supportdos@larian.com, with a brief description and your latest save (or a Dropbox or Google drive link, etc).
Each save is a folder in the '..\Documents\Larian Studios\Divinity Original Sin Enhanced Edition\PlayerProfiles\<ProfileName>\Savegames_patch' folder. In Windows Explorer you can zip a file or folder by right clicking on it/them and selecting 'Send To | Compressed (zipper) Folder'.
For OSX, saves can be zipped by right clicking the folder(s) and selecting Compress, in the folder:
~/Documents/Larian Studios/Divinity Original Sin Enhanced Edition/PlayerProfiles/<ProfileName>/Savegames_patch
Linux is similar, with the saves in the home directory.