If God has a plan for each of us, why are our acts considered faults? Are His? Aren’t we the way He designed us, in order to fulfill His plan?
God himself is the one who considers acts contrary to his commandments "faults". His plan is that we choose do his will freely. His plan includes the free will he gave us; he sets the boundries in life so he can determine what is out of bounds and what is not:
Dt :30:16, 19: In that I command thee this day to love the Lord thy God, to walk in his ways, and to keep his commandments and his statutes and his judgments, that thou mayest live and multiply: and the Lord thy God shall bless thee in the land whither thou goest to possess it. 19 I call heaven and earth to record this day against you, that I have set before you life and death, blessing and cursing: therefore choose life, that both thou and thy seed may live.
To walk with him freely is his plan.