When you observe that your heart is cold and prays unwillingly, stop praying and warm your heart by vividly representing to yourself either your own wickedness, your spiritual poverty, misery, and blindness, or the great benefits which God bestows every moment upon you and all mankind, especially upon Christians, and then pray slowly and fervently.
If you have not the time to say all the prayers, it does not matter, and you will receive incomparably greater benefit from praying fervently and not hurriedly than if you had said all your prayers hurriedly and without feeling: ‘I had rather speak five words with my understanding that ten thousand in an unknown tongue.’
But it would, of course, have been very well had we been able to say those ten thousand words in prayer with due understanding and feeling.”
St John of Kronstadt