do we really need wands?

It always best if you can make your own wands for your own personal and ritual use.

Though you can make elemental wands -
To make a wand with the element of;
Air use a piece of lilac.
Fire use cherry.
Water use driftwood.
Earth use dogwood or oak.

also it helps to have one to control the energy/power source

Based on what I've read and heard and thought, here's my understanding:

As several have said, it's about belief. If you believe you need one, you will and do.
However, it's also possibly to use your own body as a substitute. The four items usually mentioned are the Wand (Fire), the Pentacle (or coin) (Earth), The Cup (Water), And the Dagger (Air). For Spirit, sometimes a mirror is used.

Your own body can provide each of these. The cup can be any orifice - your mouth is the one that keeps it the most kid-friendly, and really is the most appropriate for most magics. Any appendage can be the dagger or wand. My suggestion is to use one hand as one, and the other as the other. I'd say that the right be the Dagger and the left the Wand. This is based on several ideas - the Right being of the God, the male side, thus Yang and war and and action; the Left is the Goddess/female/Yin/calm and controlled. Also, I'm right-handed... guess which hand I'd hold a weapon in?
The pentacle, or coin, is probably the hardest. One could use one's own body, as it has five points. You could also draw one on some part of your body (probably the torso). At the same time, it's also the easiest to construct on the fly, but it's supposedly better to use "dedicated" tools, so probably not a good idea.
Spirit and the Mirror is arguably in the eyes - the window to our souls (and windows are mirrors too). The spirit is also present in us (i.e. our souls).
Finally, there's the altar. The very body can be one's altar in this way of thinking. Just don't burn candles on yourself...