I used a translator on the the internet and I was wondering if this is correct?

Absolutely wrong. On-line translators are not at all working with any language but they're a total disaster with latin.
I suggest "Scio in te est lux " if you is singular while if you it's plural " Scio in vos est lux"

NO, no no.....online translators are not reliable! SO many things wrong. There's no verb. Intus is not even a word....

The best way to say this is:

(Ego) Credo lux in te esse
(I believe-light-in-you-to be.)
[(Eh-go) Kray-doh loox in tess-eh]

OR

(Ego) Scio (I know) lux in te esse.
[(Eh-go) skee-oh loox in tess-eh]

But the first is much better; it's more commonly used for indirect statements. "Ego" (I) is unnecessary but can be used.

Yup, I agree with dude #1 and again, don't use it for Latin! It is the biggest most diabolical language annihilation that you will ever come across.

I hope you have learned your lesson: NEVER EVER rely on ANY of those online "translators", they ALL are UTTER RUBBISH!!

No.

no its not. if ur tryin to do french it is
Je sais qu'il ya de la lumière en vous