In the passage, John 10:26-30, the ones Christ was addressing were physically hearing Him. Their sensory perception and minds were working and Christ was speaking. But they were not spiritually hearing Him, because they were not of His sheep.
The knowing of Jesus Christ occurs in the spirit, when His sheep hear his voice then Christ knows them. Therein is the direct Spiritual revelation that Jesus Christ is Lord!
The knowledge that Jesus Christ is Lord can only come from Him. Thus it is the primary Spiritual "test:"
Amen!
"My sheep hear my voice, and I know them, and they follow me" -- John 10:27
His sheep follow Him because He knows them, because He has loved them from before the foundation fo the world.
Indeed, the confession that "Jesus Christ is come in the flesh" is from Christ. So is the Church who told you that.