To believe God created Earth or that Earth is worth keeping, is clearly in contradiction to what the course says about the earth, frequently contrasting it as being the OPPOSITE of heaven and not something worthy of the Son of God. The world seen with forgiving eyes might well be "lovely", but it’s still not heaven.
Here is how the Course speaks of the "Earth"... (with my emphasis and minor comments)...
"Let me know that I am an Effect of God, and so I have the power to create like You. And as it is in HEAVEN, so on EARTH (does not mean heaven=earth, it means you have the power to create here). Your plan I follow here, and at the end I know that You will gather Your Effects into the tranquil HEAVEN of Your Love, where EARTH WILL DISAPPEAR, and separate thoughts unite in glory as the Son of God"
"His little life on EARTH was not enough to teach the mighty lesson that he learned for all of you. He will remain with you to lead you from the HELL YOU MADE (earth) to God."
"My mind will always be like yours, because we were created as equals. It was only my decision that gave me all power in HEAVEN AND EARTH (separate places). My only gift to you is to help you make the same decision."
"God has one Son, and He is the resurrection and the life. His will is done because all power is given him IN HEAVEN AND ON EARTH (separate places)."
"You cannot understand how much your Father loves you, for there is NO PARALLEL in your experience of the world (earth) to help you understand it. There is NOTHING ON EARTH with which it can compare, and nothing you have ever felt apart from Him resembles it ever so faintly."
"It is our function to remember Him (God) ON EARTH as it is given us to be His own completion IN REALITY (not on earth). So let us not forget our goal is shared. For it is that remembrance which contains the memory of God, and points the way to Him and TO THE HEAVEN (pointed to away from the Earth) of His peace"
"Father, IN HEAVEN it is different, for there, there are no needs. But HERE ON EARTH (which is not heaven) the miracle is closer to Your gifts than any other gift which I can give."
"Who can share a dream? And what can an illusion offer me? (references to earth) Yet he whom I forgive will give me gifts BEYOND the worth of ANYTHING ON EARTH. Let my forgiven brothers fill my store with HEAVEN’S treasures, WHICH ALONE ARE REAL (earth’s treasure are dreams and illusions). Thus is the law of love fulfilled. And thus Your Son arises and returns to You (reference to ascension!)."
"Let all God’s holy Thoughts surround me, and be still with me while HEAVEN’s Son is born. Let EARTHLY sounds be quiet, and the sights to which I am accustomed DISAPPEAR."
"(speaking of true perception/real world...)EARTH is being born again in new perception. Night has gone, and we have come together in the light. From here we give salvation to the world, for it is here salvation was received. The song of our rejoicing is the call to all the world (earth) that freedom is returned, that time is almost over, and God’s Son has but an instant more to wait until his Father is remembered, dreams are done, ETERNITY HAS SHINED AWAY THE WORLD (illusion of earth), and only HEAVEN now exists at all."
"(talking about Holy Spirit) His Words will work. His Words will save. His Words contain all hope, all blessing and all joy that ever can be found upon this EARTH (cus otherwise it sucks). His Words are born in God, and come to you with HEAVEN’S love upon them. Those who hear His Words have heard the song of HEAVEN, for these are the words which all merge as one at last"
"Your foot has reached the lawns that welcome you to HEAVEN’s GATE; the quiet place of peace where you await with certainty the final step of God (to take you home to heaven). How far are we progressing now from EARTH (something you do not want!)! How close are we approaching to our goal! How short the journey still to be pursued!"
""I will forgive and this will DISAPPEAR." To every apprehension, every care, every form of suffering repeat these selfsame words. And then you hold the key that opens HEAVEN’s GATE, and brings the Love of God the Father down to EARTH at last (extending Holy Spirit temporarily), to raise it up to HEAVEN. God will take this final step Himself. Do not deny the little steps He asks you take to Him."
"Forgiveness represents your function here (on earth). It is not God’s creation, for it is the means by which untruth can be undone. And who would pardon HEAVEN (opposite to earth where forgiveness is needed)? Yet on EARTH you need the means to let illusion go. Creation merely waits for your RETURN (to heaven) to be acknowledged, not to be complete. Creation cannot even be conceived of in the WORLD (definitely talking about earth here). It has no meaning here (earth is meaningless). Forgiveness is the closest it (heaven) can come to EARTH. For being HEAVEN-BORNE, it has no form at all. (Earth, place of forms, is not heaven)"
"All power is given you in EARTH and HEAVEN (two distinct places apparently). There is nothing that you cannot do."
"Repeat the Name of God and call upon your Self, Whose Name is His. Repeat His Name and all the tiny, nameless things on EARTH slip into right perspective. Those who call upon the Name of God can not mistake the nameless for the Name, nor sin for grace, nor bodies for the holy Son of God."
"There is one major difference in the role of HEAVEN’s messengers which sets them off from those the world (earth) appoints. The messages which they deliver are intended first for them. And it is only as they can accept them for themselves that they become able to bring them further, and to give them everywhere that they were meant to be. Like EARTHLY messengers (but only like, not the same as), they did not write the messages they bear, but they become their first receivers in the truest sense, receiving to prepare themselves to give."
"Now a quiet time has come in which we put away the toys of guilt, and lock our quaint and childish thoughts of sin forever from the pure and holy minds of HEAVEN’s CHILDREN and the Son of God. We pause but for a moment more, to play our final happy game UPON THIS EARTH And then we GO (to heaven) to take our rightful place where truth abides and games are meaningless."
"HEAVEN remains your ONE ALTERNATIVE to THIS STRANGE WORLD YOU MADE and all its ways; its shifting patterns and uncertain goals, its painful pleasures and its tragic joys. God made no contradictions. What denies its own existence and attacks itself is not of Him. He did not make two minds, with HEAVEN as the glad effect of one, and EARTH THE OTHER’S SORRY OUTCOME WHICH IS HEAVEN’s OPPOSITE IN EVERY WAY."
"You are indeed essential to God’s plan. Just as your light increases every light that shines IN HEAVEN so your joy ON EARTH calls to all minds to let their sorrows go, and take their place beside you (in heaven) in God’s plan"
"How could there be a meeting place at all where EARTH AND HEAVEN can be reconciled within a mind where both of them exist? (Clearly they cannot both exist) The mind that sees illusions (earth) thinks them real. They have existence in that they are thoughts. And yet they are not real because the mind that thinks these thoughts is separate from God."
"Jesus is the manifestation of the Holy Spirit, Whom he called down UPON THE EARTH after HE ASCENDED INTO HEAVEN, or became completely identified with the Christ, the Son of God as He created Him. The Holy Spirit, being a creation of the one Creator, creating with Him and in His likeness or spirit, is ETERNAL and has never changed. He was "called down upon the EARTH" in the sense that it was now possible to accept Him and to hear His Voice. His is the Voice for God, and has therefore taken form. This form is not His reality, which God alone knows along with Christ, His real Son, Who is part of Him."
"There IS no change in immortality, and HEAVEN knows it not. Yet here on EARTH (place that changes), it has a double purpose, for it can be made to teach opposing things"
"What hatred claimed is given up to love, and freedom lights up every living thing and lifts it into HEAVEN, where the lights grow ever brighter as each one comes HOME. The incomplete is made complete again, and HEAVEN’s joy has been increased because what is its own has been restored to it."
I pulled the quotes from a searchable urtext version. There are MANY MORE references to being "in heaven" versus "on earth", making it clear and obvious they are both distinct and OPPOSITE, and that only heaven is real, only heaven is what you want, and only heaven is befitting the Son of God.
God did not create the earth. This world is not our home. There is no life outside of heaven! The world - earth - holds nothing that we want. There is no world (earth). A teacher of God will gladly give up all the pleasures of the world (earth) (beacuse Heaven is FAR BETTER!) :-) Heaven is EVERYTHING, Earth is NOTHING.