The second portion of Krias Shema is found in this week's parsha: "V'haya im shemoah tishmeu el mitzvosi" - And if you listen, you will listen to My mitzvos. (Devarim 11, 13). Rashi explains the seemingly superfluous wording of the pasuk as follows. "If you listen to the previous commandments, then you will listen to the subsequent commandments. Likewise, the Torah writes, 'If you forget you will forget' implying that if you begin to forget, you will end up forgetting everything as [Chazal] state, 'If you forsake me (the Torah) for one day, I will forsake you for two days.'"
The Yerushalmi brings a parable to convey this idea. When two friends part, and one walks eastward while his friends walks westward in the exact opposite direction, after a day of walking they are in reality a distance of two days apart. Rav Wolbe (Ma'amarei Yemei Ratzon pg. 364) comments that the parable implies that Chazal's words about the Torah forsaking a person are not metaphorical. Rather, if one forsakes the Torah, the Torah will actually distance itself and forsake that person. When he wishes to return to the Torah he will not find it in the place he left it and he will have to toil twice as hard to reconnect to the Torah.
The same applies to tefillah. Rashi in Meseches Brachos (4b) cites another Yerushalmi which describes one who fails to daven Shemoneh Esrei immediately after reciting the Shema and its blessings. This can be compared to the friend of a king who knocked on the palace door and before receiving a response he turned around and left. When the king opened the door and saw that his friend left, he too, turned around and left. Rather a person should draw Hashem close with praises of Yetzias Mitzrayim and He will come close, and while Hashem is close he should request his needs. If we draw Hashem close He will reciprocate, while if we turn around and distance ourselves, He will conduct Himself in a similar fashion.
The Ramban (Shemos 3, 13) mentioned last week, quotes a Medrash that encapsulates this idea. Hashem told Moshe to relate to Bnei Yisroel that He reciprocates their actions. If they open their hands to give tzedakah, Hashem will open His storehouses and bestow great bounty upon them. In other words we are the determining factor as to our relationship with Hashem. If we distance ourselves from Him He will respond likewise, while if we attempt to come close to Him, He too, as per the exact amount of effort we expended in achieving this goal, will draw Himself close to us.
The summer is a time that allows many people to change the daily schedule maintained during the rest of the year. However, one must take great care not to forsake Torah study or tefillah. One day missed translates into two days of work regaining what was lost. A single day should not pass entirely devoid of tefillah or Torah study, and the harder the effort involved in retaining our relationship with Hashem, the closer Hashem will draw Himself to us!