God Declared: When I see the Blood I will pass over you.
God Himself will Passover when He Sees the Blood.
It is God who Sees the Blood, not the people who put it on.
That Blood is not seen by us, because it is not given to us to see.
We must use Faith.
Though we many not see it or feel it, we Simply Believe, for the Blood is for God to See.
If the Blood has been Applied, there is no more need to be worried.