Modalism is the belief that God is one person who manifested Himself in different modes or forms in contrast to Trinitarianism which affirms One God Eternally Existing in Three Persons. Per the three modes doctrine, during the Incarnation Jesus Christ was God revealing Himself in one form while the Holy Spirit at Pentecost was God in yet a third form.
Modalism is likely to be the most common heresy regarding the nature of God. It varies in its expressions in today’s societies but one of the most common groups adhering to this theological error is the United Pentecostal Church. We cannot overlook the dangers this teaching brings as Trinitarian Doctrine is essential to a proper understanding of the Biblical God, how the Persons relate to each other, and how They relate to mankind. T.D. Jakes is a popular teacher who has a history of modalistic doctrine and is still very soft in his language today.