It seems that when things in a person's life are going well, it's easy to pray with concentration and be devoted to the service of the creator. However, when things turn sour these items are more difficult to maintain - one might not pray with as much concentration and do the mitzvot not whole-heartedly.
How can one maintain the same level of devotion no matter what situation he or she is in?
You ask this question on the Friday of parasha Tzav. In a dvar Torah on that parasha, the Lubavitcher Rebbe (Likkutei Sichot vol I, pp. 217-219, cited in R Sachs' Torah studies p. 159) comments on the verse Vayikra 6:6
אֵ֗שׁ תָּמִ֛יד תּוּקַ֥ד עַל־הַמִּזְבֵּ֖חַ לֹ֥א תִכְבֶֽה
Fire shall be kept burning upon the altar continually; it shall not go out
and on the Talmud Yerushalmi comment on this verse (Yoma 4:6)
"Continually - even on Shabbat; continually - even in a state of impurity"
He writes that every aspect of the physical Sanctuary has its counterpart of the inward Sanctuary within the soul of the Jew.
His heart is the altar. And corresponding to the two altars of the Sanctuary, the outer and the inner, are the outer and inner levels of the heart, its surface personality and its essential core. The altar on which the continual fire was to be set was the outer one. And for the Jew this means that the fire of his love for God must be outward, open and revealed.
To the man who has traveled so far on the part of separation that he feels he has now no link with God, the Talmud says "It shall not go out - even in a state of impurity" for the fire does not go out. A spark always burns in the recesses of the heart. It can be fanned into flame. And if it is fed with the fuel of love, it will burn continually.
The essential implication of this is that every Jew constitutes a Sanctuary to G‑d. And even if he learns Torah and fulfils the commandments, if the continual fire is missing, the Divine presence will not dwell within him.
The Jew must bring life, involvement, fire, to the three aspects of his religious existence: Torah, prayer and the practice of charity. (Pirkei Avot 1:2)
see the full dvar Torah for more details.
Now in my personal experience, the way to "warm up" divine service when things get tough are
in terms of Torah learning, to try and learn Torah that warms the heart, which depending on the individual can be the weekly parasha with a good commentary, hassidut, or Mesilat Yesharim
in terms of prayer, to pick up one prayer (starting with shema and shmonei esrei) and to slow down massively for 5 minutes to really focus on the words and try to understand the meaning of the prayer. Some do this with a different part of the prayer every week to cover enough material very slowly over the week. Other tools that can help are an interlinear siddur to help understand the Hebrew or a book on prayer (e.g., Praying with fire)
Behatzlacha!
By learning a little bit of Sha'ar HaBitahhon everyday.
Personally, I've found that when things are not going so well is exactly when my devotion increases -- it's clear that I can't fix whatever the problem is on my own and I need God's help. Which, really, is true for all of us all the time, but sometimes we don't notice and claim too much credit for ourselves.
Pirke Avot 2:1 says:
Know what is above from you: a seeing eye, a listening ear, and all your deeds being inscribed in a book.
In context it looks like the intent is more toward "be good and remember you're being watched", but in times of difficulty I find comfort there -- it's saying I'm not alone and Someone is watching and listening.
No source, just personal experience.
The low periods are called in mussar "days of hate", see Sefer Hayashar bellow. The status of a man in these days is called in kabalistic language "Mochin deKatnut" (in loose translation small mindedness).
The low periods are no less nessessary and constructive than the good periods. How best exploit these periods? Why this kind of switches are so important? You can find a magistral development in Rabbi Menachem Mendel miVitebsk the greatest student of the Magid Mimezritsh (in the book Peri Ets). I tried to present below 2 texts that illustrate his point of view (Drush le Shabbat Teshuva, Parashat Mikets).The Peri Ets adresses also the topic of prayer. We can "ignite" our spirit on tefila in low periods. He explain how to benefit from these periods. The Sefer Hayashar describes how to get ready for fluctuations in interest to Avoda.
See Peri Ets Drush leShabbat Teshuva and I want to highlight a couple of important points.
And then, see Pri Ets Mikets and remember this few lines
לכן ענין התפילה שהוא ההתקשרות [1] צריך ליתן עיניו למטה שישים עיניו בהשגחתו [2] יתברך מטה מטה וממילא יהיה לבו למעלה ויהיה קשור למעלה משבעת ימי הבנין, שהיא החכמה שהיא למעלה מן ההשגה שהרי אינו יכול להשיג חכמתו יתברך בכל סיבה [3] ואם כן יותר שהאדם נופל בשפל סתר המדרגה ממילא משיג ומבין הלא ה' זו[4]. שהרי אינו משיג ומבין טובת הסיבה מה שאין כן כשהולך וטוב אינו משיג כל כך חכמתו יתברך שהיא נעלמה[5] שהרי סיבותיו מושגים לטובה
Chapter 6, Sod Yeme Haahava vehasin'a. To preparing in advance in order to go through the low periods, accepting the changes. An anecdotal extract (remember, it is not the Shulchan Aruch)
וכן אם יתחיל להתפלל ויקוץ בתפילה, יתפלל ימים בשבוע או פעם אחת [6] ביום
actually seems to be the opposite. when things go well people don't pray so much. It's usually one things are tough does a person realize he needs the help of the Almighty.
So in those times, use it as an opportunity to pray to God in your own words outside of your regular prayers as the Chafetz Chaim wrote:
"In summation, all the many calamities that come on us and that we are not saved from them is because we are not screaming and outpouring in prayer over them. If we would pray and would pour out before HaKadosh Baruch Hu, certainly our prayers and supplications would not return empty. And it's not enough for a person to pray the shemonei esrei three times a day, rather a few times per day, a person needs to pour out prayers and supplications in solitude, in his house, from the depths of his heart. Because the three prayers (shemonei esrei) are already fixed in his mouth and he doesn't take them to heart so much. But if a person would contemplate in solitude and make a cheshbon hanefesh on his personal situation, his great poverty and his many toils, and for all this to live on crusty bread and water, then he will pour out his heart like water in front of Hashem, yisborach, and the prayer will go out with deep kavana and with a broken heart and a lowly spirit. A prayer like this will certainly not return empty. And then when his soul is bitter on him, on his situation and his weak standing, and he drops supplications before HaKadosh Baruch Hu, he should also remember the great pain of Hashem yisborach, because he also, so to speak, does not have rest. In all our suffering He suffers..." Chafetz Chaim - Likutei Amarim ch.11
