Let's just clarify. Was it Adam's will to sin or was it God's will that Adam would sin?
Can you explain why God would have to take additional steps to prevent someone from believing if God has already proclaimed that they could not possibly believe without God causing them to believe?
God ordained the fall, by His Sovereign design. The unanswered question is: Why?
There are no steps needed to prevent a human from believing. Humans are incapable of believing without God graciously saving them and giving them faith.
Romans 3 clearly tells us that no one ever seeks after God. The opposite is true. All humans are on a one way path toward hell. The only escape is if God intervenes and plucks them out of the stream and places them on the narrow road.