James 1:22-25 But be ye doers of the word, and not hearers only, deceiving your own selves. For if any be a hearer of the word, and not a doer, he is like to a man beholding his natural face in a glass: For he beholdeth himself, and goeth his way, and straightway forgetteth what manner of man he was. But whoso looketh into the perfect law of liberty, and continueth therein, he being not a forgetful hearer, but a doer of the work, this man shall be blessed in his deed.

There is only one way that anyone can do the Word. That is by God's process. God's process is this: God speaks. We listen. God's faith (supernatural belief) comes to us. Faith gives us access to His Grace. Grace, God's free gift of righteousness, does the work of God through us, which changes us in our very nature, making us holy and freeing us from sin's slavery. (some caveats about hearing God's Voice)

The Holy Spirit tells us that this perfect law of liberty is like a mirror, and, if we continue in this perfect law of liberty, then we will be changed. The Holy Spirit says it in James 1:22-25 and several other places in the Bible:  

2 Corinthians 3:18 But we all, with unveiled (the veil is the flesh) face beholding as in a mirror (those who have been created in the image of God) the glory of the Lord, are transfigured into the same image from glory to glory, even as by the Spirit of the Lord. Literal

1 Corinthians 13:12 For now we see through a glass, darkly; but then face to face: now I know in part; but then shall I know even as also I am known.

Jesus Christ is the perfect law of Liberty.

1 John 3:2 really says that now, we are the immature children of God, and what we shall be has not yet been unveiled, the flesh has not been taken away to reveal it. But when Christ is unveiled, when the flesh is taken away to reveal Christ, we shall see Him as He is, and we shall be changed to be like Him.

Jesus is the Truth. It is the truth that sets us free. The truth is reality. When we see things as they really are, we see that we are born into Christ the Body, which is joined to Christ the Head. We have a sinful nature, but we are the Christ. When we forget this, we fall into sin. When we abide in this, it is because we maintain fellowship with the Father and the Son. We yield our mind, our soul, to the Holy Spirit, and allow the Holy Spirit to lead us and fill us with power both to will and to do His good pleasure.