God's invitation comes to each youth, “My son, give Me thine heart; I will keep it pure; I will satisfy its longings with true happiness.” God loves to make the youth happy, and that is why He would have them give their hearts into His keeping, that all the God-given faculties of the being may be kept in a vigorous, healthful condition. They are holding God's gift of life. He makes the heart beat; He gives strength to every faculty. Pure enjoyment will not debase one of God's gifts. We sin against our own bodies, and sin against God, when seeking pleasures which separate our affections from God. The youth are to consider that they are placed in the world on trial, to see whether they have characters that will fit them to live with angels. MYP 408.2
When your associates urge you into paths of vice and folly, and all around you are tempting you to forget God, to destroy the capabilities God has intrusted to you, and to debase all that is noble in your nature, resist them. Remember that you are the Lord's property, bought with a price, the suffering and agony of the Son of God.... MYP 409.1
The Lord Jesus claims your service. He loves you. If you doubt His love, look to Calvary. The light reflected from the cross shows you the magnitude of that love which no tongue can tell. “He that keepeth My commandments, he it is that loveth Me.” We are to become acquainted by diligent study with the commandments of God; and then show that we are His obedient sons and daughters. MYP 409.2