I was searching for John Piper's thoughts on a certain topic and found this article...SO helpful, encouraging, and 'in-your-face'. =)
1.2. Forsaking Wicked Ways and Thoughts
To seek the Lord means to forsake wicked ways and unrighteous thoughts (v. 7).
Let the wicked forsake his way, and the unrighteous man his thoughts.
If you take seriously the positive side of seeking God, you have to take seriously the negative side of turning from behaviors and thoughts that offend him. You cannot seek God and practice sin or plan sin at the same time.
If you call out to God, "O God, I need you, help me!" one of the very first things that will happen in answer to that prayer is that God will awaken your conscience to something in your life that needs to be forsaken. If God answers your call in that way and you refuse to forsake what your conscience condemns, then you cease to seek God, and your words become empty (as in Isaiah 58:1-2). You can't seek God where he is not found, in sin.
It would be like a man who leaves his wife, moves into his own apartment, has a regular sexual affair alongside his marriage, and then gets on the phone and "calls" his wife and "seeks" his wife. And she says, "Have you forsaken this woman?" And he says, "No, I can't." Then she will rightly say, "Then you are not seeking me. Your call is empty. You will seek me and find me as your wife when you forsake her and all others for me alone, just like you vowed!"
Seeking the Lord means forsaking the ways and the thoughts that are displeasing and dishonoring to him. You can't seek him where his is not found—in sin.
Now lets look back through the book of Isaiah to see what else it means to seek the Lord.