It is the will to pray that is the essence of prayer, and the desire to find God, to see Him and to love Him is the one thing that matters. If you have desired to know Him and love Him, you have already done what was expected of you, and it is much better to desire God without being able to think clearly of Him, than to have marvelous thoughts about Him without desiring to enter into union with His will.
No matter how distracted you may be, pray by peaceful, even perhaps inarticulate, efforts to center your heart upon God, Who is present to you in spite of all that may be going through your mind.
His presence does not depend on your thoughts of Him. He is unfailingly there; if He were not, you could not even exist. The memory of His unfailing presence is the surest anchor for our minds and hearts in the storm of distraction and temptation…
From Thomas Merton, “New Seeds of Contemplation”