Yes, all Protestants accept the doctrine of the Trinity. The simple answer is "Not all do." First the definition of the term: "Protestant" has the basic meaning of "one who protests." Eventually, the term came to mean a "member of any Western church outside the Roman communion." While there are many discussions and heated debates over the matter, the simplicity is this: Man is not to privately interpret the Word of God (II Peter 1:20-21). As such, it is clearly given in scripture that we are to believe that Jesus Christ is the Son of God (e.g., John 6:69, 20:30-31, Acts 8:37, I John 5:13, etc.). There is not one passage in The Bible (regardless of which version used) that says we are to believe otherwise. That is, there are no passages that read in the form of, "Thou shalt believe that Jesus Christ is ___." All of the passages used to support the doctrine of the trinity require private interpretation--exactly opposite of that given in II Peter 1:20-21. Now we must ask the question, "Why is it important to have the doctrine of the trinity established?" The simple answer again is, "In the end times, how else will so many people be deceived into submitting to the beast (an apparent god on earth)?" It is quite interesting to consider this supposition in light of Chapter 13 of the Revelation of Jesus Christ to John.
Of course the Catholic Church believes in the Trinity. The Catholic Church is the Body of Christ on earth, and He is the second Person of the Trinity. Here is a summary of the Church's teaching from the Catechism:rom The Catechism of the Catholic Church, second edition, English translation 1994
Glossary: Trinity: the mystery of one God in three Persons: Father, Son, and Holy Spirit. The revealed truth of the Holy Trinity is at the very root of the church’s living faith as expressed in the Creed. The mystery of the Trinity in itself is inaccessible to the human mind and is the object of faith only because it is revealed by Jesus Christ, the divine Son of the Eternal Father. (See paragraphs 232, 237, 249, 253-256)
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The Old Testament proclaimed the Father clearly, but the Son more obscurely. The New Testament revealed the Son and gave us a glimpse of the divinity of the Spirit. Now the Spirit dwells among us and grants us a clearer vision of himself. It was not prudent, when the divinity of the Father had not yet been confessed, to proclaim the Son openly and, when the divinity of the Son was not yet admitted, to add the Holy Spirit as an extra burden, to speak somewhat daringly . . . By advancing and progressing “from glory to glory,” the light of the Trinity will shine in ever more brilliant rays. (St. Gregory of Nazianzuz, Oratio theol., 5, 26 (=Oratio 31, 26): J.P. Migne, ed., Patrologia Graeca {Paris, 1857-1866} 36)
Yes. The Lutheran church believes in the Triune God (three in one) also called the Holy Trinity. There are even numerous Lutheran churches called Holy Trinity.
Yes, of course Catholics believe in the the Trinity.
The Church of England and Anglican Church in general, the Lutheran Church and the Roman Catholics certainly do, although there are others.
Holy Trinity Church Marylebone was created in 1828.
Ursuline Church of the Holy Trinity was created in 1726.
Holy Trinity Brompton Church was created in 1829.
Holy Trinity Church - Manhattan - was created in 1898.
Holy Trinity Church - Nashville - was created in 1852.
Holy Trinity Church - Aleppo - was created in 1965.
Holy Trinity Church - Berlin - was created in 1739.
Holy Trinity Platt Church was created in 1846.
Holy Trinity Episcopal Church - Manhattan - ended in 1895.
Greek Orthodox Church of the Holy Trinity was created in 1953.
Holy Trinity Church - Old Swedes - was created in 1799.