Personally I can be certain I am growing in grace if I have an increasing sense of my own sinfulness and my own unworthiness; if I see more and more the blackness of my own heart. If I am satisfied with myself I am not growing; if I am not satisfied, it is a sign of growth. Let me put it in this way – if I am more concerned about being delivered from sin than from particular sins it is a sign that I am growing. The child is interested in particular sins, the man who is growing is aware of a sinful nature from which he longs to be delivered.
What about the Christian’s attitude toward the world? Well, the sign of growth in grace is an increasing understanding of the nature of the spiritual conflict that is going on in this world. In other words, the man who is growing is the man who is less and less surprised at what is happening, and at the state of the world. The man who is growing in grace desires the world less, and is less tempted by it. But above all, I would say that the sign of growth in grace is when a man is grieved by the state of the world.
But, lastly, the best of all tests of growth is a man’s attitude to God. Do I love God more than I did? Do I desire God’s glory more than I used to do? Oh! let me put it in one phrase – Do I desire Him more and more, and not just what He can do for me?…There is no better test of growth than that a man desires God because He is God, desires to know God, is not so much concerned to be getting things from God as to be in His Presence and to feel the radiance and to know himself in the blessed filial relationship…Delivery from the realm of experiment and experience and gifts, and all these things which are perfectly legitimate and quite all right as long as we do not live for them, and being increasingly drawn to the centre and desiring Him and Him alone.
– Martyn Lloyd-Jones, Expository Sermons on 2 Peter, p. 251