You can still understand how God works and should see to understand Him and know His will. These last three keys will complete the foundation of understanding how God works.
First, despite even significant errors in judgment and sinful choices on our part, God still isn't finished with you. Look through your Bible and you'll find countless stories of men and women who have sinned significantly and still been used by God, such as Samson, David, and Elijah.
We may have detours and some may limit our overall effectiveness. We may not be as great later as before, but some of these have a greater influence later.
Secondly, God intends for you to learn from your mistakes and may possibly even do greater things through you than you may have done without them. It took Saul's and Moses' murder of others for God to turn them around...and He used them more after the fact than before.
Will you lay aside the past (good OR bad) and press on towards the mark?
Finally, sometimes forfeiting God's will means you must forfeit some thing or freedoms you hold dear. It may cost you dearly to follow God, to seek Him and His will, but the riches are inestimable.
The riches and rewards of following God's will are more than we could imagine, just as Hi will is greater than what we imagine. Sin may derail us from God's will, but it may also be the avenue He uses to turn us towards Him.
These ten keys we've discussed over the past three weeks are the foundation for knowing God's will. They are necessary to understand if one is to know and do God's will.