1. We are all one IN CHRIST JESUS. We are then one spiritually but we are not all one race.
2. We should have a beef in marrying non-Christians if they despise God and will not consider becoming a child of God...the One True God!
3. The new covenant didn't change God's Words. Only one seeks to change God's laws:
Words of Christ:
Matthew 5:18 For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled.
Prophesy concerning Satan:
Daniel 7:25 And he shall speak great words against the most High, and shall wear out the saints of the most High, and think to change times and laws: and they shall be given into his hand until a time and times and the dividing of time.
4. The argument with "plants" is one in which I ask you to see the meaning figuratively. What does "earth, seed, trees" etc. symbolize? A clue:
Isaiah 55:12 For ye shall go out with joy, and be led forth with peace: the mountains and the hills shall break forth before you into singing, and all the trees of the field shall clap their hands.