So god is not capable of executing his plan, then? Do you think the "sin" thing was just an oversight on his part?
God's plan is to have fellowship with intelligent beings that he created. In order for Him to be certain that these created beings love Him for sure, He gave them free will. He knew this would all unfold as it is. However, He set it up so that "if" mankind followed "His" original plan we could have lived in paradise in perfect fellowship right from the start. That was the original design. Then, as He knew it would happen, man and his free will didn't follow the plan. All he had to do is not eat the fruit of the knowledge of good and evil...... that was all. But, pride got in his way and he wanted to be "like God" as Satan said he would.
It's like raising kids. You teach them not to do stuff. You tell them they will get punished. AND you know they are going to do it sometime. It's inevitable because they are beings with free will. They are not robots.
God could have made us like robots but that is not what He wanted. He wanted us to choose Him out of our own free will. Belief in Jesus Christ by faith and no tangible smoking gun evidence of the gospel being the truth, is the way we show Him that we have chosen Him.
Believe me, as soon as a human makes that decision, by faith to totally trust in the free gift of salvation, the existence of Jesus being God made man and dying on the cross to pay for their sins to be pardoned.....as soon as this happens and is a true change of heart and heart deep belief by faith....everything is made clear and the faith is no longer a faith it is true knowledge of the total biblical truth of the gospel and the historical account of the universe as written in the scriptures. Until then..... you will never see the truth and you will be blown to and fro by the words of men who profess to be wise but are actually fools.
There is no way to describe it but once it is felt, you cannot deny it.
So, God set it all up but knew we would screw it up and already had a plan to fix it by preparing a way for the price of the sinner to be pardoned.
Even Satan knew this. Every thing Satan has done has been to deter Christ from dying on the cross as was needed or to convince man that God or Christ don't exist or to convince man that he himself, Satan, doesn't exist.
If Christ fulfilled all that was needed, as God made man to provide a pardon to any man who asked for it.
And if a man believes that Christ is God made man.
And if man believes that the gift of salvation is real.
And if man asks for this pardon.....with no in you face, smoking gun, three dimensional apparition telling him it is true evidence...... then..... Satan has failed.
If Satan can convince you that any one of these is false....you have been deceived and Satan wins, you lose and God will be greatly saddened by His loss of one of His precious beings that He created in His image to fellowship with Him.