Discipline is necessary for us to focus our attention and develop and refine our skills.  A disciplined person has integrity and can make difficult but necessary choices.  Most people do not like discipline, especially children.  When we have to rise above our impulses and desires and do something challenging, it can appear as a punishment.  The struggles of living a good and effective Christian life, especially when we actively choose virtue over vice, are allowed by God and necessary for reaching spiritual maturity.  God invites us to share in His Kingdom.  Hearing and accepting that invitation requires an active, conscious decision on our part.  Reforming our lives and changing how we do things does not come easily.  But it is precisely what is necessary for us to enter through the narrow gate that leads to life.  Discipline is essential if we are going to discover our desire for union with our Creator and live in God's house.  In this way, we will not risk finding the door locked when we need it to be open.