The Bible says that offerings were to be made for sins that were done in ignorance (see scripture below). Therefore when we are covered by the all-atoning blood of the Lamb (Jesus), He covers us from the sins that we commit in 'innocence', or rather ignorance. But of course you have to believe in what He has done through His sacrifice and blood in order for this to apply to you.
Numbers 15.24-29. Then it shall be, if ought be committed by ignorance without the knowledge of the congregation, that all the congregation shall offer one young bullock for a burnt offering, for a sweet savour unto the LORD, with his meat offering, and his drink offering, according to the manner, and one kid of the goats for a sin offering. And the priest shall make an atonement for all the congregation of the children of Israel, and it shall be forgiven them; for it is ignorance: and they shall bring their offering, a sacrifice made by fire unto the LORD, and their sin offering before the LORD, for their ignorance: And it shall be forgiven all the congregation of the children of Israel, and the stranger that sojourneth among them; seeing all the people were in ignorance. And if any soul sin through ignorance, then he shall bring a she goat of the first year for a sin offering. And the priest shall make an atonement for the soul that sinneth ignorantly, when he sinneth by ignorance before the LORD, to make an atonement for him; and it shall be forgiven him. Ye shall have one law for him that sinneth through ignorance, both for him that is born among the children of Israel, and for the stranger that sojourneth among them.