Re: I need advice 
I haven’t gone through the responses already posted against your questions but I didnt’ want to be biased so will reply based on your post only.
First of all, understand that you two are different people with individual traits. The training process isn’t a recycle. So prove yourself a better trainer and let him learn whatever you know already. That being said, you will be in a difficult position if both of you knew the same type of work and be at an equal level in terms of skills, position and package etc, may be its time for you to come forward and show off in front of the management. It seems like you have just being doing your job and your management doesn’t know about it. If this new person has better interpersonal skills and has managed to convince the upper management that he’s doing a good job, it is time for you to develop those skills as well.
However, if you still want to politically handle everything and don’t want his interference in anything a simple way to do it would be dividing the tasks between the two. So nothing overlaps. You do your tasks and report it to the management and he does his share of work and report to the management. Have a meeting with the immediate boss and make him/her understand that two people doing the same work is practically inefficient. I am not sure about your industry so cannot provide any specific reference but you might want to grow your skills by taking up some certification for future growth.