I thank God, whom I serve with a clear conscience... (2 Timothy 1:3)
We are born with a operative conscience. It is that God given sensibility to discern right from wrong. However, we are also born with a sin nature that gradually corrupts our conscience and suppresses our awareness of God and His righteousness; For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men who suppress the truth in unrighteousness, because that which is known about God is evident to them; for God made it evident to them. (Roman 1:18, 19)
Unless we are saved by God's grace and are spiritually reborn a new person in Christ, our conscience will continue to become less effective in discerning and restraining sin; And just as they did not see fit to acknowledge God any longer, God gave them over to a depraved mind, to do those things which are not proper, being filled with all unrighteous, wickedness, greed, evil; full of envy murder, strife, deceit, malice; they are gossips, slanderers, haters of God, insolent, arrogant, boastful, inventors of evil, disobedient to parents, without understanding, untrustworthy, unloving, unmerciful. (Romans 1:28-31)
But the conscience of those of us who are born-again is being continually renewed by the Holy Spirit who indwells us. Our conscience is now effective in guiding us away from sin and toward righteousness; ...their conscience bearing witness and their thoughts alternately accusing or else defending them... (Romans 2:15)
With an effective conscience, instructed by God's word and the Holy Spirit, comes the responsibility to faithfully follow it's leading; Therefore, to the one who knows the right thing to do and does not do it, to him it is sin. (James 4:17)
As a Christian, you have peace with God and, you can also have the peace of God in any circumstance, when you serve Him with a clear conscience. Maranatha!