Living as a Child of God

Today's devotional was interesting to me because a class I have been taking at church and a lot of sermons I have heard recently talk about our main goal as Christians should be to share the Gospel with others all the time. I like what the woman said that before we do that, we need to make sure we are living right, as examples of Christ, lest our sharing of the Gospel comes across as insincere. I tried to apply this to my life today as I was running errands and shopping...the bank told me they wouldn't cash my check and I needed to return it to my HR dept. :-( I said a prayer and I didn't get an attitude and stayed patient--tried to think how Jesus would handle the situation :-) and in the end, things turned out fine. I took the scripture "let everything you say be good and helpful" Eph.4:29 and tried to do that throughout the rest of the day...one lady at Macy's asked me what I did for a living and then was asking me about how she could get a job. I think I helped her a little bit with that, but how would I bring up Jesus...or her being saved? Today was an overall good, positive day, but I wasn't sure how to share Jesus with anyone...for all those people that encountered me today, I was friendly to them, but did they know I was 'representing' Jesus Christ? I think eventually the Gospel needs to be shared aloud, but how do you do that naturally and sincerely?