Sometimes I can feel like if I'm not living perfectly, then I'm being a bad witness for Christ.
Of course, as we're living in the already but not yet, there is still indwelling sin within each one of us, so until I die, or Christ returns, I will still sin. This means that perfectionism is not possible, and Jesus doesn't expect me to live a perfect life.
So my neighbours and non-Christian friends won't be able to see a perfect person in this life (other than Christ). Instead what I can show them hopefully is a repentant person who is gradually changing.
Rather than trying to be perfect witnesses, I'm trying to be honest about my failings, and my sin, and instead demonstrate continual repentance. A repentance that shows how amazing Jesus is, that he's freed me up to be able to admit my sin, and that he's provided forgiveness so that I can openly repent, not fearing punishment.