You all know that I have been sustained throughout my life by three saving graces - my family, my friends, and a faith in the power of resilience and hope. These graces have carried me through difficult times and they have brought more joy to the good times than I ever could have imagined.

This quote is saying that the speaker has been sustained (supported) in life by three things: their family (their relatives), their friends, and their faith (belief) in the power of resilience (not giving up easily) and hope (a feeling that something good will happen). These things have been helping the speaker through bad times and have made the good times even better than they could have imagined.