It was a type and shadow of what the Cross of Calvary.
The way you are thinking marhig, I am assuming had you been in the OT times you would not have put the blood on the door posts of your house.
No it isn't, it's Christ's blood covering our hearts, so that the destroyer won't enter in. It's nothing to do with Christ's natural blood. How can his natural blood cover you or me. It's his life within and him living through us that covers us, that that's what God wants to see, and it happens when we have faith and obey God and become a living sacrifice doing the will of God and not living to please ourselves
I believe in a do and obey God gospel, not a do nothing and live my own life and go to heaven regardless of what I do wrong gospel, as seems to be what OSAS teaches! That's not what is taught in the Bible.
That happened once before in the garden of Eden, God gave a commandment and told Adam what to do, and along came Satan, "don't worry if you disobey God, you won't surely die", but, Adam did die spiritually and was cast out.
A bit like OSAS "don't worry, you can still sin, God won't see it all is forgiven"
That's a false teaching, once we know God, we are held accountable for what we do before God. We are forgiven of our past sins at repentance not future sins too.
Romans 3
Whom God hath set forth to be a propitiation through faith in his blood, to declare his righteousness for the remission of sins that are past, through the forbearance of God
Any gospel that preaches that you are saved even if you carry on wilfully sinning is a false gospel.
Once we repent, we are to turn from sin and go sin no more. If we carry on living in our fleshly lusts, then we haven't got the spirit. Because with the spirit, our conscience should be so strong, that we find it near impossible to wilfully sin!
And if we have the spirit of God within, then turn away and start living to please our fleshly lusts, then we won't have the spirit for long.
We're going nowhere. You only talk of the cross, there's nothing at all about the life of Jesus. Just death.