Here's a gospel of salvation that would apply to anyone in any inhabited planet. There are many, many, many planets with humans in them. Earth is not the only one. This is where my about 35 years of spiritual journey has brought me to:
"The spiritual technique of SALVATION occurs when an individual accepts and is "quickened" by the expression of God's LOVE and MERCY. Salvation is yours when you get a revelation of God's love and mercy: a revelation or understanding-experience that causes you to open your heart to God, to trust Him, to welcome Him into your life; to surrender all to Him as your Father. These acts bring you to a place where you begin to see others as your brothers and sisters and you develop FAITH in your eternal salvation - that you will exist in and with God forever. Your heart becomes totally committed to doing His will. This is possible because of the GRACE and GOODNESS of God. Herein is your salvation."