Here's a very valuable insight from George Mueller, taken from The Autobiography Of George Muller... (Underlining is added by me.)
May 7, 1841. It has recently pleased the Lord to teach me a truth, irrespective of human instrumentality, as far as I know, the benefit of which I have not lost, though now, while preparing the fifth edition for the press, more than fourteen years have since passed away.
The point is this: I saw more clearly than ever that the first great and primary business to which I ought to attend every day was, to have my soul happy in the Lord. The first thing to be concerned about was not how much I might serve the Lord, how I might glorify the Lord; but how I might get my soul into a happy state, and how my inner man might be nourished.
For I might seek to set the truth before the unconverted, I might seek to benefit believers, I might seek to relieve the distressed, I might in other ways seek to behave myself as it becomes a child of God in this world; and yet, not being happy in the Lord, and not being nourished and strengthened in my inner man day by day, all this might not be attended to in a right spirit. Before this time my practice had been, at least for ten years previously, as an habitual thing to give myself to prayer, after having dressed myself in the morning.
Now, I saw that the most important thing I had to do was to give myself to the reading of the word of God, and to meditation on it, that thus my heart might be comforted, encouraged, warned, reproved, instructed; and that thus, by means of the word of God, whilst meditating on it, my heart might be brought into experimental [experiential] communion with the Lord.
I began therefore to meditate on the New Testament from the beginning, early in the morning. The first thing I did, after having asked in a few words the Lord's blessing upon his precious word, was, to begin to meditate on the word of God, searching as it were into every verse, to get blessing out of it; not for the sake of the public ministry of the word, not for the sake of preaching on what I had meditated upon, but for the sake of obtaining food for my own soul.
The result I have found to be almost invariably this, that after a very few minutes my soul has been led to confession, or to thanksgiving, or to intercession, or to supplication; so that, though I did not, as it were, give myself to prayer, but to meditation, yet it turned almost immediately more or less into prayer.
When thus I have been for a while making confession or intercession, or supplication, or have given thanks, I go on to the next words or verse, turning all, as I go on, into prayer for myself or others, as the word may lead to it, but still continually keeping before me that food for my own soul is the object of my meditation.
The result of this is, that there is always a good deal of confession, thanksgiving, supplication, or intercession mingled with my meditation, and that my inner man almost invariably is even sensibly nourished and strengthened, and that by breakfast time, with rare exceptions, I am in a peaceful if not happy state of heart.
Thus also the Lord is pleased to communicate unto me that which, either very soon after or at a later time, I have found to become food for other believers, though it was not for the sake of the public ministry of the word that I gave myself to meditation, but for the profit of my own inner man.
(Excerpt taken from the Kindle edition.)