Read Exodus 11 and Exodus 12...
It's the account of the last plague..... that of the first born of all..... and the whole reason of the Passover.
The First born of humans of course could have 80 years old or 8 hours old.... it made no difference whatsoever (age isn't mentioned.... it didn't matter). Age is entirely irrelevant.
See Exodus 12:21-23 The Angel of Death came to all first born, but God provided a way for the first born of the Hebrews to escape and be exempted. The parents of the first born did this .... in obedience and faith.... trusting God. And when the Angel of Death came, the Angel recognized the blood and the faith and obedience of the parents, and their child (whether 8 hours old or 8 years old or 80 years old) was saved.
COULD God has just deleted the whole bit about the Passover, the Lamb, the Blood, etc., etc., etc. and just said "I'll exempt all Hebrew first born?" Sure. But He didn't.
COULD God have said, "But don't do this unless the first born is over the age of X because the Angel wouldn't do anything to those under that age?" Yes, but He didn't.
COULD God have said, "The faith and obedience of the parents means squat so forget all about the Passover, the Lamb, the blood, the door?" Sure. But He said the opposite.
Did God USE the faith of the parents to save their first born? Yes
Was the faith/obedience of the parents entirely irrelevant, useless and if they had done anything, God would have been rendered impotent to save those children? Nope.
Did the faith of the parents save their children? No (God did).
But did God use what He commanded the parents to do? Obviously yes.
The Bible clearly states that all humans are sinful - and deserving of the Angel of Death and Hell itself. Not just first born, but all born.
COULD God have just said, "Yeah, but no biggie.... I'll just wink at sin and forget all I said about it until the person reaches their X birthday (and I won't tell you what birthday that is). But He didn't.
One COULD believe that God nonetheless does that in every case of every person (Hindu, Atheist whatever) even though there's NOTHING that REMOTELY states that. One could even believe that children should be killed prior to that age as the only way to guarentee Heaven for them. But again, there's nothing in Scripture, nothing in the life of the church for over 1500 years, nothing that remotely indicates that is the truth.
We are told to GO.... Baptize..... Teach.
We do have Christians at least from 63 AD doing that for their children.
They saw the promise "for you and your children."
It was something done in faith, as family, in community.
Every faithful, Christian parent proceeded in faith and obedience for their children until 1523 when one German invented a dogma that says, "Thou art FORBIDDEN to do that!"
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