How does the great seeker walk by grace when he has the faith to be perfect?

If I understand you correctly, you are disappointed with God because despite of your desire for perfection and the help of His grace, you continue to sin. This is what I believe in. First, it is possible to be perfect because God will not issue this command if it is impossible to attain. Second, it can only be attained through the power of grace, since our own human powers alone cannot make us perfect. But the crux of the matter is, we can only be as perfect as God wills us to be. Remember st. Paul, with his 'thorn in the flesh' that even with his prayers, God wanted st. Paul to endure this weakness? So what it boils down is, that we should trust God that He will transform us to the kind of person that will please Him the most.