You can use what is available as long as you do it that is what counts especially if you want to do this asap. But you should probably be sure that candle wasn't used for or intended for xtian things before out of respect. I may have failed on that one back in the day though and the Gods didn't say anything i found a red candle but it was laying around the house and my dad wss a pastor that lead an xtian church when I was a teen and did this. I did it when they left for church. Oh well just bringing it up to think about.