If something is illegal (which marijuana still is in your state), then it certainly wouldn't be God's will for you to break the law, and I sincerely hope you won't.
But even if it does become legal where you live (as it already has in some states), I strongly urge you not to use that as an excuse to come under the influence of this or any other drug, including alcohol. God gave our minds to us (as well as our bodies and souls), and it is never His will for us to abuse them or allow them to be controlled by anything that alters our judgment or places us (and others) in danger. The Bible bluntly says, "Do not get drunk.... Instead, be filled with the Spirit" (Ephesians 5:18).
The real question, however, is this: What place does God have in your life? Are you honestly seeking His will, no matter what it is -- or are you simply seeking His approval for what you already want to do? Be honest with yourself, but most of all, be honest before God. He made you, and life's greatest joy comes from knowing Him and discovering His will for your life.
Only Christ can truly give you the lasting, inner peace you seek -- and that's why I urge you to turn to Him and ask Him to come into your life. Don't be deceived by the false promise of drugs. Jesus' promise is true: "Peace I leave with you; my peace I give you" (John 14:27).