I know lying is a sin. But are certain circumstances okay? Would it be okay to lie to someone so you can give them a surprise party? How about lying to protect someone, or lying so they don't get hurt? Are there any times when lying is okay, or should we never lie?
Please cite the chapter and verse where you found that information. We have to assess the context to give an appropriate answer. Romans carefully explains that Christians don't sin, so one wonders why Christians keep obsessing obsessively about sins.
According to my studies, sin, singular, is the absence of spirit. Adam had a spirit but it died and so he was unable to bequeath a spirit to his offspring. That is why everybody is born in sin, not because Mommy and Daddy did the big nasty. That is why a savior had to die in our place and make it possible to create a new spirit for us.
Sins, plural, are mistakes, such as throwing a dart and missing the bullseye. Christians are baptised into Christ's death, and dead bodies don't commit sins, so sins are not an issue for Christians. There is no more forgiveness. Either you believe in Jesus and are saved or you don't believe and are lost.
I am not aware of any place in the bible that says "Thou shalt not lie." There is that verse in the O.T. that says "Thou shalt not bear false witness," but that does not apply to Christians. Besides, it's hard to imagine a Christian thinking that love for his neighbors might be manifested by bearing false witness. So the first thing we need to address is the verse that makes you think a Christian can commit a sin by lying. Then we can examine specific instances where loving one's neighbor can be served by lying.