So, anyone can easily comprehend what verse 18 says unless they have a bias against it.
1 Peter 1:2 clearly speaks of Jesus's blood being sprinkled on the mercy seat.
1 Pet 1:2 Elect according to the foreknowledge of God the Father, through sanctification of the Spirit, unto obedience and sprinkling of the blood of Jesus Christ: Grace unto you, and peace, be multiplied.
It is not clear as all that.
The verse speaks of the sprinkling of blood. The verses says NOTHING about it being sprinkled on the mercy seat. Claiming it clearly says this when it says nothing of the sort is highly fallacious. You might *infer* that its an allusion to sprinkling on the mercy seat, but to claim the passage clearly says it is begging the question.
I think we would all agree that the whole concept of Christ's blood and sacrifice is drawn from OT practices. So if we find in the OT law that blood was sprinkled on the mercy seat from sacrifices, then a reasonable conclusion *might* be that I Pet 1:2 is an allusion to this. Furthermore, if you were able to show that the only reference to blood being sprinkled in the OT law was that sprinkled on the mercy, then such a parallel would become very strong - strong enough that it would be unreasonable to deny that I Pet 1:2 is referring to sprinkling blood on the mercy seat.
However, even if the above is true,
a. its still fallacious to claim that this is what the passage *says*
b. and its highly fallacious to insist that it is meant literally w/o some clear supporting evidence. Its possible that I Pet 1:2 is making a reference to something that is symbolically true and not literally.
But, even if I Pet 1:2 is to be taken literally, there is an even larger problem for your "clear" reading. The problem is that sprinkling of blood in the OT is not only found in reference to the mercy seat. Instead we find that blood is sprinkled on the altar (Exodus 24:6;29:20), around the altar (Leviticus 1:5), it is sprinkled on the people (Exodus 24:8), its sprinkled on Aaron (Exodus 29:21), it is sprinkled before the veil of the Holy place (Leviticus 4:6). So, claiming its "clearly" talking about sprinkling blood on the mercy seat is w/o warrant. It might be speaking of the sprinkling on the people, the altar, the high priest, before the tabernacle...or all of these together.
So, clearly, the verse is not so clear as you claim
