If you never knew evil, you would never know what good is.
The area you mention, plan, in this area IMO, appears to have flew by many nests haha.
Same with enmity (war) between the seeds.
Most suggest it is only referring to one seed = Jesus and I would suggest it's all seeds (peoples), war going on in ones head between your good and evil.
Hence the evils victory in the likes of the Mid-east, all the beheading's etc.
Don't like it, well.............Isa 55:8 - 11 - For my thoughts are not your thoughts, neither are your ways my ways, saith the LORD.
For as the heavens are higher than the earth, so are my ways higher than your ways, and my thoughts than your thoughts.
For as the rain cometh down, and the snow from heaven, and returneth not thither, but watereth the earth, and maketh it bring forth and bud, that it may give seed to the sower, and bread to the eater:
So shall my word (Bread) be that goeth forth out of my mouth: it shall not return unto me void, but it shall accomplish that which I please, and it shall prosper in the thing whereto I sent it.
Hence, Jesus said he was the Bread = Now exalted and by inheritance received a name after the Father = The Word --> The Word OF God.
And sure enough, Jesus came out of the mouth (Spirit) of God, angels message to Mary.
Jesus became the Door to The Word (God) = The Word of God and this door was planed for before Jesus even existed and this plan is known as Glory and was held via God before the world existed with God John 17:5 as per the Greek and not the average man maid version of John 17:5.
Expand
