In a classic experiment, researchers found a strong correlation between a child's ability to delay gratification and his/her success in life (as defined in many ways). In the most loving manner, patience teaches one more than the ability be quiet while waiting. Take a look at the following two videos...
"O son of man! For everything there is a sign. The sign of love is fortitude under My decree and patience under My trials." (Bahá'u'lláh, The Hidden Words, Arabic 48)
"It behoveth whosoever hath set his face towards the Most Sublime Horizon to cleave tenaciously unto the cord of patience, and to put his reliance in God, the Help in Peril, the Unconstrained." (Baha'u'llah)
and, last but not least, this one reminds me of the children in the video most (though a marshmallow test is not so dire)...
"...God will add unto the recompense with which He shall reward Us, for having sustained with persevering patience the tribulations We have suffered. He, verily, shall increase the reward of them that endure with patience." (Baha'u'llah)