Q: Did our first parents continue in the estate wherein they were created?
A: Our first parents, being left to the freedom of their own will, fell from the estate wherein they were created, by sinning against God.

Genesis 3:6-8, 13. And when the woman saw that the tree was good for food, and that it was pleasant to the eyes, and a tree to be desired to make one wise, she took of the fruit thereof, and did eat, and gave also unto her husband with her; and he did eat. And the eyes of them both were opened, and they knew that they were naked; and they sewed fig leaves together, and made themselves aprons. And they heard the voice of the Lord God walking in the garden in the cool of the day: and Adam and his wife hid themselves from the presence of the Lord God amongst the trees of the garden... And the Lord God said unto the woman, What is this that thou hast done? And the woman said, The serpent beguiled me, and I did eat.
2 Corinthians 11:3. But I fear, lest by any means, as the serpent beguiled Eve through his subtilty, so your minds should be corrupted from the simplicity that is in Christ.

Westminster Project - Read Francis Beattie on the Covenant of Works/Life