Any time we decide to take possession of a promise of God, when the enemy becomes aware of it, they come with an attack attempt to steal our victory. That's a Kingdom key right there - they come to ATTEMPT steal our victory because we're already guaranteed to win and get what we want because of Christ. Don't miss this now, this is good teaching ... you will have your promise if you don't quit. All promises are yes and amen in Christ. The enemy coming against you is just an ATTEMPT to cause you faint, and if you know who you are and what the written Word says you have no reason to grow weary.
We see this happening with Abraham all the way back in Genesis (nothing new under the sun) when Father identified the land he and his offspring would possess. Abraham wasn't able to just take any promise without some time type of test or trial from God or war from an enemy. That's another imporant piece of wisdom right there, don't miss it - tests and trials of faith come from the Lord (for example, sacrificing Isaac) and warfare comes from the enemy (for example, Abaraham having to fight five kings to save Lot). Don't ever accuse Father of bringing you warfare; what He does is offer a reward if you can believe beyond natural circumstances - that's a test of faith. Warfare requires an enemy and if you belong to and love Jehovah, you're not His enemy and He's not fighting against you.