JOEL - I am not sure that "complete" faith is possible for most people in this life. Our faith grows a little each day. How do we know when it is complete?
Faith implies action. So for our faith to grow we must keep moving forward in our obedience to God's commandments; in living His gospel principles; repenting of our sins; and continuing service to Him and His children. Our faith can also grow as we listen to the personal spiritual witnesses and read the scriptural records of former and latter-day special witnesses(eg. Apostles), whom God has called and who have experienced spiritual realities beyond this world. As we experience the blessings from doing these things our faith in God will grow.
True faith is enduring and leads to an assurance that one's efforts have not gone unnoticed and that God is pleased with one's attitude and effort to implement the principles of the gospel of Jesus Christ in one's personal life. I believe this assurance we feel can be used as a measure of how strong our faith really is.