Depends on what type of believer. The nominal, shallow, or lukewarm believer can indeed fall away (Luke 8:13).
However, the Christian with the fear of the LORD (Jeremiah 32:38-40, Psalms 19:9) who has a heart faith that is unto righteousness (Romans 10:10), cannot (John 5:24, John 6:47, John 10:27-30) (here we go again...)
The blood of Jesus does indeed sanctify (Hebrews 13:12, Hebrews 10:29, 1 John 1:7)...if you would be willing to look up the verses.
That makes no sense at all. What He is saying is that Christian believers who say to Him Lord, Lord, and do not do what He says are not true Christians at all...He literally has never known them.
You do understand that Jesus is God? There is only one mediator between God and man.
So you are saying that Mary is the mother of Jesus' Deity? That would make Mary God in some fashion...and I suppose that this is the next doctrine to broach the Catholic spectrum of belief.
I don't think that
@Truther believes that Jesus isn't God...he is Oneness: among the ranks of those who believe that Jesus is the Father.
It does in my book.
You should take a wild look at some Protestant churches...you won't find the same apostasy there...but a moving of the Holy Spirit (not in all Protestant denominations; but in some: you just need to have a keen eye for knowing living water when you see it).