Strange Doctrines: If you were lost and your father sent someone to teach you the way to get home that would be true doctrine. Yet, someone else comes along teaching a way which will carry you about from the way your father taught you. You know their teaching is strange because it does not agree with the word--the teaching or doctrine--of your father. God's word is his doctrine sent down from heaven. Any time you are taught by men, compare what men teach to what God teaches in his written word. If what they instruct agrees with God it is true doctrine; if what they teach does not agree with God's word, if it is not in agreement with the person and work of Christ Jesus, or if it is foreign to the teaching that salvation is by grace, then you can be sure they are teaching strange doctrines--be not carried about (Heb 13: 9.)