Some things you are missing here...Most Protestants get their theology from the scriptures, only...As a result, they pour over the scriptures for truth and understanding...The bible is the 'final authority' for all matters of faith and practice...
Your religion on the other hand, relies on the writings and opinions of it's old and newer church fathers and tries to make the scriptures line up with those things that you call tradition...
Those that spend even a little time in the scriptures know that the Body of Christ is made up of believers...And ONLY believers...
It would be ignorant to say that all Catholics are believers, or all Protestants are believers...Therefore, it is IMPOSSIBLE that your religion is the Body of Christ...
Secondly, any honest student of the scriptures know that salvation does not come from the Body of Christ (the believers)...It comes from the Head, Jesus Christ...It is biblical IMPOSSIBLE that salvation comes from your church thru your religion...
So, yes Christ has given the Catholic Church, along with the Orthodox Church, the fullness of the means of salvation via the Sacraments or what the East refers to as the Holy Mysteries.
Again, this is not only a lie, it comes from the Father of Lies...
There are no Holy Mysteries...The mysteries that were spoken of by the apostles have been revealed...They are no longer mysteries...
Your's is just a catch-phrase to make your church sound spiritual, religious...Nothing biblical about it...
And the part YOU'RE missing is the bible isn't comprehensive enough to be the "final authority." Your doctrines insist it is, so y'all have to contrive all manner of NON scriptural excuses to give interpretations the authority of scripture.