See if there is any offensive way in me, and lead me in the way everlasting.
In Barnes' commentary he states that the Hebrew word here actually refers to idol worship....
According to this, the prayer is that God would search him and see if there was anything in him that partook of the nature of idolatry, or of defection from the true religion; any tendency to go back from God, to worship other gods, to leave the worship of the true God. As idolatry comprehends the sum of all that is evil, as being alienation from the true God, the prayer is that there might be nothing found in his heart which tended to alienate him from God - would indicate unfaithfulness or want of attachment to him.
And lead me in the way everlasting - The way which leads to eternal life; the path which I may tread forever. In any other way than in the service of God his steps must be arrested. He must encounter his Maker in judgment, and be cut off, and consigned to woe. The path to heaven is one which man may steadily pursue; one, in reference to which death itself is really no interruption - for the journey commenced here will be continued through the dark valley, and continued forevermore. Death does not interrupt the journey of the righteous for a moment. It is the same journey continued - as when we cross a narrow stream, and are on the same path still.
What a wonderful ending to a beautiful and intimate Psalm.
Our Creator God knows us more intimately than we even know ourselves. He can penetrate into our subconscious and our very souls. He knows every wicked thought or inclination. And yet He loves us still.
He does not love us because we are worthy of our own merit to be loved.
He loves us because He created us in His image, He knit us together in our mother's wombs, we are fearfully and wonderfully made.
And as we allow Him to penetrate our souls with refiner's fire, we will glorify Him now here on earth and in heaven forever. Amen!