Contrary to some notions, God actually wants us to be happy. He wants us to have joy, to experience the beauty of his creations, to know the love of parenthood and family, to feel of His love for us, and to live according to His Spirit. He only wants us to experience the negative so that we can appreciate the beautiful things He has in store for us. The concept of religion which teaches that one must deprive oneself of all pleasure in some sort of austere self-deprivation of mind, body, and spirit is false.
We are only to deprive ourselves of those worldly pleasures which enslave the human mind, body, and spirit. Satan mimics the plan of the Lord. He says, "men are that they might have fleeting pleasure." God's plan is that we have lasting joy in this world and eternal joy in the world to come. This sort of joy can only come when the body and spirit are joined together, the elements are eternal, and spirit and element, inseparably connected, receive a fullness of joy; And when separated , man cannot receive a fullness of joy (DC 93:33-34).
The Lord has provided many ways for us to experience this divine joy while here on the earth. He has given us the privilege of parenthood, that we may "have joy and rejoicing" in our posterity. The scriptures also teach us that the Spirit will bring us joy, Verily, verily, I say unto you, I will impart unto you of my Spirit which shall enlighten your mind, which shall fill your soul with joy (DC 11:13). The Israelites knew that newlyweds were to have joy in their marriage, When a man hath taken a new wife, he shall not go out to war, neither shall he be charged with any business: but he shall be free at home one year, and shall cheer up his wife (Deut 24:5). Of this earthly joy, Brigham Young taught:
"'Mormonism' has done everything for me that ever has been done for me on the earth; it has made me happy; it has made me wealthy and comfortable; it has filled me with good feelings, with joy and rejoicing. Whereas, before I possessed the spirit of the Gospel I was troubled with that which I hear others complain of, that is, with, at times, feeling cast down, gloomy, and despondent; with everything wearing to me, at times, a dreary aspect." (Discourses of Brigham Young, compiled by John A. Widstoe, p. 452)
The Lord also has provided for those who are worthy to experience eternal joy, If in this life only we have hope in Christ, we are of all men most miserable (1 Cor 15:19) This is the reason for our creation, for God's work is to bring to pass the immortality and eternal life of man (Moses 1:39). The eternal joy of God's love is likened to the fruit of the tree of life, for it is the final reward of the righteous. What greater joy could one possibly experience than to hear the Savior say, Well done, thou good and faithful servant: thou hast been faithful over a few things, I will make thee ruler over many things: enter thou into the joy of thy lord (Matt 25:21)?
Joseph Fielding Smith
"Adam's transgression was banishment from the presence of God and bringing the physical death into the world. The majority in the religious world maintain that every child born into this world is tainted with 'original sin,' or partakes of Adam's transgression in his birth. The second Article of Faith contradicts this foolish and erroneous doctrine." (Answers to Gospel Questions, vol. 1, p. 82)