Each day before you leave the house, you likely look in the mirror to make sure everything looks appropriate. The mirror reflects an image you recognise and choose to maintain. The Word of God is likened to a mirror; it holds the power to build your spiritual self-image.
At times, Christians read Scripture, see who they are in Christ, then forget what they saw in the mirror of the Word. Consequently, they move through the day without letting that self-portrait guide their actions. The issue is not a lack of transformation—you have been completely transformed, joined with His Spirit. However, it is doing the Word that causes your true self-image to become clearer and more fully expressed in your daily life.