I wonder which teaching you refer to. Do you mean the teaching that Jesus is not God but a creature created by God, "the firstborn of all creation"? (Colossians 1:15, 1 Corinthians 11:3) For a thorough explanation of our view in this subject see here.

Or do you mean the teaching that the soul is mortal and that when we die we go to the same place that Adam went to when he died, the dust? (Gen 3:19; Ezequiel 18:4) For an explanation about our understanding of this issue, please see here.

Or, let me see, are you upset about the teaching that paradise will actually be right here on Earth instead of in heaven, once Jehovah God cleanses the Earth and removes wicked people from it? (Psalms 37:10, 11, 29) Please see here for more on that.

I guess you could also mean the understanding Jehovah's witnesses have that the punishment for sinners is simply to die and not to burn eternally on fire. (Romans 6:7) See here if you want to know why Jehovah's witnesses believe that.

I could go on and on, listing things where Jehovah's witnesses beliefs differ from most other denominations. However, please note that there are strong reasons why Jehovah's witnesses have conscientiously decided to aligned their beliefs regarding those subjects differently than others.

Jehovah's witnesses believe that there are sincere people in all religions. We ourselves are sincerely trying to be the type of worshiper that "worships the father with spirit and truth". (John 4:23, 24) If you sincerely think we are mistaken in any such point, please let us know. I mean that would be the right thing to do, the Christian thing to do. Right? If you are interested in having a reasonable and respectful discussion about any such topic, please send me a PM. This forum and this thread is not the place to do so.