This has always been the teaching of the Roman Catholic Church (established 33AD) ... it is in no way a personal assertion.
I was Catholic educated all through grade school & high school. I was an Aler Boy and an Ad Aitare Dei Medal boy scout. I never recall being taught that.
I do not now beleive that. Beilief in Christ's divinity & his sacrifice for our salvation are not the only aspects of Vhristianity, but they are the most important.