God values a good conscience in us, and of course, He wants us to value it as well.
What He said to the Israelites shows why a good conscience is valuable,
“You shall say before the LORD your God: ‘I have removed the holy tithe from my house, and also have given them to the Levite…according to all Your commandments which You have commanded me; I have not transgressed Your commandments, nor have I forgotten them…Look down from Your holy habitation, from heaven, and bless Your people Israel and the land which You have given us, just as You swore to our fathers’” (Deuteronomy 26:13-15).
He wanted the Israelites to be able to state the way they had lived, and that they wanted Him to bless them.
Likewise, the value of a good conscience for a Christian is being able to speak to God freely of the way you have lived your life, and then being able to ask Him to bless you.