rooted

Romans 11:17-24

Paul describes a tree where certain branches have been cut off and other branches have been grafted in. The grafted in branches become part of the main tree.
Paul warns the Gentiles, as grafted in branches, not to be arrogant about their new position because a) they do not bring life to the root but are brought to life by the root and b) it would be easy for God to break them off and graft the original branches back in. Paul's point is that the nation of Israel was cut off because of unbelief and we were grafted in by faith - not by any merit in ourselves. If we lose faith and become arrogant (thinking, like Israel did, that we somehow merited our position), we are in danger of being cut off.
This is not the picture of God that we generally hold to. Paul actually points this out: we see both the kindness and the sterness of God in this. He is so kind and gracious and merciful that he grafted me in but he is stern - he is not soft. This is a God that I can worship because he is strong and fills me with wonder (and, at times, fear - not in the sense that he is a boogey man but in the sense that he is an incredibly powerful and wild king).
On a side note, I am incredibly frustrated with the NIV study bible since they never have notes on the interesting verses. For example, they remain strangely silent on v. 21 and the end of v. 22. Have some balls!!