But there is only one prayer that the Lord gave us specifically. That is the only God-given Prayer. I think there is a difference between that God-givne Prayer and those we make up.
I could not agree with you more. It is among the only "no-lose" prayers that we know of by Christ's examples. Again from the passage:
1 John 5:14-15 : 14 This is the confidence we have in approaching God: that if we ask anything according to his will, he hears us. 15 And if we know that he hears us — whatever we ask — we know that we have what we asked of him.
In this case, when we make it up, there is a full possibility of "losing". That is, if it is not in accordance with God's will. With the Lord's Prayer, that is not possible. My point was to note that God does actively wish for us to attempt to pray in His will in addition to the Lord's Prayer.