Reverend Barber announced his retirement in December but stayed to assist the church with COVID and until a new pastor could be put in place.
Saturday's tribute included a concert and banquet with MSNBC's Joy Reid as the keynote speaker.
President Biden sent a video message to Barber, and Vice President Kamala Harris sent a letter congratulating him on 30 years of leading an impactful ministry.
Reverend Barber will give his farewell sermon Sunday on June 18.