One of my favorite hymns of consecration is "Take My Life and Let It Be" by Frances Ridley Havergal. I have recently begun reading the book Kept For the Master's Use: The Life Fully Devoted to God by Havergal, where she takes each couplet of that great hymn and expands on it.
In the first chapter, she changes the word "take" in each couplet and changes it to "keep," making the point that we not only want God to take our lives, but to keep them and use them how He wishes. That is truly the meaning of consecration. She then gives this convicting explanation of what our motivation should be in asking for this:
Consecration is not a religiously selfish thing. If it sinks into that, it ceases to be consecration. We want our lives kept, not that we may feel happy, and be saved the distress consequent on wandering, and get the power with God and man, and all the other privileges linked with it. We shall have all this, because the lower is included in the higher; but our true aim, if the love of Christ constrains us, will be far beyond this.
Not for "me" at all, but "for Jesus"; not for my safety, but for His glory; not for my comfort, but for His joy; not that I may find rest, but that He may see the travail of His soul and be satisfied! Yes, for Him I want to be kept. Kept for His use; Kept to be His witness; kept for His joy! Kept for Him, that in me He may show forth some tiny sparkle of His light and beauty; kept to do His will and His work in His own way; kept (it may be) to suffer for His sake; kept for Him, that He may do just what He wants with me; kept, so that no other lord shall have any more dominion over me, but that Jesus shall have all there is to have - little enough, indeed, but not divided or diminished by any other claim. Is not this, O you who love the Lord - is not this worth living for, worth asking for, worth trusting for? This is consecration, and I cannot begin to tell you the blessedness of it.