If you sometimes have evil thoughs. Does that mean you are an evil person ?
If you sometimes have evil thoughts, that definitely does not mean that you are an evil person. After all, until we are perfect, we have flaws.
Swami Kriyananda used the following analogy: Most people look like a stained glass window on a dark day: the colors of the various panes of glass are rather murky. But as we grow spiritually, and thus live at a higher level of energy, it is as though the sun is shining on the stained glass: we see the vivid color of the individual panes of glass, so both our virtues and our vices become more apparent. That is good news, because only when we awaken to the fact that we still have vices, can we work on overcoming them.
The more we strive toward perfection, the more those vices diminish and eventually disappear. Just keep striving, keep meditating, until your desire for the Divine becomes so compelling that evil thoughts no longer arise.