"Let your light shine before others, so that they may see your good works and give glory to your Father who is in heaven.” Matthew 5:16
This should be the position, posture and product of all Christian life. Not that we shine with our own light, but that we reflect the glory of the one who brings true life!. If people cannot see the change of energy and attitude as you go through your day, examine yourself to see if you are truly living the renewed life that only Jesus can bring to you!
There will always be times when we don't feel like we can represent Christ because of what we have done or what we have done to us, but suck it up person of God and move on! Jesus has showed us the way....let us follow Him one step at a time! With our master we will stand or fall...and stand we will!
Blessings on your day!