It is true that orthodox Christian denominations uphold the Trinity doctrine and denominations that reject the Trinity are considered to be outside of orthodox Christianity. That would include Jehovah's Witnesses and Latter Day Saints who deny that the Trinity is biblical.

A June 2015 Watchtower article said that all Trinitarian churches that do not promote the name Jehovah are part of the Antichrist. They believe that all Catholic and Protestant denominations are part of Babylon the Great, the world empire of false religion, soon to be destroyed at Armageddon.

It is for this reason that Jehovah's Witnesses will have nothing to do with the Apostles' Creed (or any other creed, for that matter). Indeed, Jehovah's Witnesses deny they are either Catholic or Protestant.

However, the Apostle's Creed is NOT promoting the Trinity. It is simply a statement of faith. All Christians should be able to agree with it, although sometimes people misunderstand the expression "holy Catholic church." Catholic in this context means universal. As for the expression that Jesus descended into hell, the Witnesses say that hell is simply the common grave of mankind. They also say that the body of Jesus disappeared and what came out of the tomb was a spirit creature, and that Jesus is known in heaven as Michael the Archangel.

Source: What Does The Bible REALLY Teach

It is true that orthodox Christian denominations uphold the Trinity doctrine and denominations that reject the Trinity are considered to be outside of orthodox Christianity. That would include Jehovah's Witnesses and Latter Day Saints who deny that the Trinity is biblical.

A June 2015 Watchtower article said that all Trinitarian churches that do not promote the name Jehovah are part of the Antichrist. They believe that all Catholic and Protestant denominations are part of Babylon the Great, the world empire of false religion, soon to be destroyed at Armageddon.

It is for this reason that Jehovah's Witnesses will have nothing to do with the Apostles' Creed (or any other creed, for that matter). Indeed, Jehovah's Witnesses deny they are either Catholic or Protestant.

However, the Apostle's Creed is NOT promoting the Trinity. It is simply a statement of faith. All Christians should be able to agree with it, although sometimes people misunderstand the expression "holy Catholic church." Catholic in this context means universal. As for the expression that Jesus descended into hell, the Witnesses say that hell is simply the common grave of mankind. They also say that the body of Jesus disappeared and what came out of the tomb was a spirit creature, and that Jesus is known in heaven as Michael the Archangel.

Source: What Does The Bible Really Teach