The ultimate object of a Sunday School teacher should be in humble dependence upon divine grace, to impart that religious knowledge; to produce those religious impressions; and to form those religious habits, in the minds of the children, which shall be crowned with the SALVATION OF THEIR IMMORTAL SOULS. Or, in other words, to be instrumental in producing that conviction of sin; that repentance towards God; that faith in the Lord Jesus Christ; that habitual subjection in heart and life to the authority of the scriptures, which constitute at once the form and power of GENUINE GODLINESS.
Here then you see your object, and you perceive that it includes every other in itself. To aim at anything lower than this, as your last, and largest purpose; to be content with only some general improvement of character, when you are encouraged to hope for an entire renovation of the heart—or merely with the formation of moral habits, when such as are truly pious may be expected, is to conduct the objects of your benevolence with decency down into the grave, without attempting to provide them with the means of a glorious resurrection out of it. To train them up in the way of sincere and undefiled religion, is an object of such immense importance, that compared with this, an ability to read and write, or even all the elegant refinements of life, have not the weight of a feather in their destiny.
(found at www.monergism.com)