Carl Lentz -- best known as Justin Bieber's former pastor and mentor -- says his church booted him because he cheated on his wife.
A day after the Hillsong East Coast church announced they'd fired Pastor Lentz over "leadership issues and breaches of trust, plus a recent revelation of moral failures," Carl revealed those failures included infidelity.
Lentz says ... "I was unfaithful in my marriage, the most important relationship in my life and held accountable for that. This failure is on me, and me alone and I take full responsibility for my actions.