My instincts would be to find a point near the beginning of the video clip where you can “see” a sound, like a person beginning to speak or the bride coming down the isle (music). Put a clip marker there. Put the audio on the timeline and listen for what you saw in the video. Mark that with a clip marker.
Align the two markers.
Repeat this process near the end of the video. Rate stretch the audio to align the end markers.
Jump to the middle of the video and see if things are in sync…if not, you have a project from hell!