@ChabadShlucha,
@Joseph,
Serving Hashem from fear of punishment or wanting to receive Schar, is not the ultimate level of Avodas Hashem, and far from it. As the Rambam says in Hilchos Teshuva, Perek 10:1
אל יאמר אדם הריני עושה מצות התורה ועוסק בחכמתה כדי שאקבל כל הברכות הכתובות בה או כדי שאזכה לחיי העולם הבא, ואפרוש מן העבירות שהזהירה תורה מהן כדי שאנצל מן הקללות הכתובות בתורה או כדי שלא אכרת מחיי העולם הבא. אין ראוי לעבוד את ה’ על הדרך הזה, שהעובד על דרך זה הוא עובד מיראה ואינה מעלת הנביאים ולא מעלת החכמים. ואין עובדים ה’ על דרך זה אלא עמי הארץ והנשים והקטנים שמחנכין אותן לעבוד מיראה עד שתרבה דעתן ויעבדו מאהבה:
English Translation:
A person should not say: “I will fulfill the mitzvot of the Torah and occupy myself in its wisdom in order to receive all the blessings which are contained within it or in order to merit the life of the world to come.”
“[Similarly,] I will separate myself from all the sins which the Torah warned against so that I will be saved from all the curses contained in the Torah or so that [my soul] will not be cut off from the life of the world to come.”
It is not fitting to serve God in this manner. A person whose service is motivated by these factors is considered one who serves out of fear. He is not on the level of the prophets or of the wise.
The only ones who serve, God in this manner are common people, women, and minors. They are trained to serve God out of fear until their knowledge increases and they serve out of love.
From here we see two important points.
1. Children do need to be educated in serving Hashem out of from and for Schar. This is what’s taught in virtually every frum school. That’s the way children can relate to serving Hashem. However,
2. We must recognize that while we do get punished for transgressing Hashems will, and we do get rewarded for listening to Hashem, this is not the reason why we serve him. We must serve Hashem out of love, not fear or gaining reward.