I choose the joy of God instead of pain.

Pain is a wrong perspective. When it is experienced in any form, it is a proof of self-deception. It is not a fact at all. There is no form it takes that will not disappear if seen aright. For pain proclaims God cruel. How could it be real in any form? It witnesses to God the Father's hatred of His Son, the sinfulness He sees in him, and His insane desire for revenge and death.
Can such projections be attested to? Can they be anything but wholly false? Pain is but witness to the Son's mistakes in what he thinks he is. It is a dream of fierce retaliation for a crime that could not be committed; for attack on what is wholly unassailable. It is a nightmare of abandonment by an Eternal Love, Which could not leave the Son whom It created out of love.
Pain is a sign illusions reign in place of truth. It demonstrates God is denied, confused with fear, perceived as mad, and seen as traitor to Himself. If God is real, there is no pain. If pain is real, there is no God. For vengeance is not part of love. And fear, denying love and using pain to prove that God is dead, has shown that death is victor over life. The body is the Son of God, corruptible in death, as mortal as the Father he has slain.
Peace to such foolishness! The time has come to laugh at such insane ideas. There is no need to think of them as savage crimes, or secret sins with weighty consequence. Who but a madman could conceive of them as cause of anything? Their witness, pain, is mad as they, and no more to be feared than the insane illusions which it shields, and tries to demonstrate must still be true.
It is your thoughts alone that cause you pain. Nothing external to your mind can hurt or injure you in any way. There is no cause beyond yourself that can reach down and bring oppression. No one but yourself affects you. There is nothing in the world that has the power to make you ill or sad, or weak or frail. But it is you who have the power to dominate all things you see by merely recognizing what you are. As you perceive the harmlessness in them, they will accept your holy will as theirs. And what was seen as fearful now becomes a source of innocence and holiness.
My holy brother, think of this awhile: The world you see does nothing. It has no effects at all. It merely represents your thoughts. And it will change entirely as you elect to change your mind, and choose the joy of God as what you really want. Your Self is radiant in this holy joy, unchanged, unchanging and unchangeable, forever and forever. And would you deny a little corner of your mind its own inheritance, and keep it as a hospital for pain; a sickly place where living things must come at last to die?
The world may seem to cause you pain. And yet the world, as causeless, has no power to cause. As an effect, it cannot make effects. As an illusion, it is what you wish. Your idle wishes represent its pains. Your strange desires bring it evil dreams. Your thoughts of death envelop it in fear, while in your kind forgiveness does it live.
Pain is the thought of evil taking form, and working havoc in your holy mind. Pain is the ransom you have gladly paid not to be free. In pain is God denied the Son He loves. In pain does fear appear to triumph over love, and time replace eternity and Heaven. And the world becomes a cruel and a bitter place, where sorrow rules and little joys give way before the onslaught of the savage pain that waits to end all joy in misery.
Lay down your arms, and come without defense into the quiet place where Heaven's peace holds all things still at last. Lay down all thoughts of danger and of fear. Let no attack enter with you. Lay down the cruel sword of judgment that you hold against your throat, and put aside the withering assaults with which you seek to hide your holiness.
Here will you understand there is no pain. Here does the joy of God belong to you. This is the day when it is given you to realize the lesson that contains all of salvation's power. It is this: Pain is illusion; joy, reality. Pain is but sleep; joy is awakening. Pain is deception; joy alone is truth.
And so again we make the only choice that ever can be made; we choose between illusions and the truth, or pain and joy, or hell and Heaven. Let our gratitude unto our Teacher fill our hearts, as we are free to choose our joy instead of pain, our holiness in place of sin, the peace of God instead of conflict, and the light of Heaven for the darkness of the world.

- Jesus Christ in A Course in Miracles, Lesson 190