This image might be a little jarring at first, but we have to remember our place and our role.
We have the light in us, we are not the light. Jesus saves, not me. So our role is on that shows love and teaches truth, but it is the role of the Spirit of God to convict.
To convict means that we need to have faith that God will work in others just has he worked in me. We need to have faith that God is patient with others just as he has been patient with me.
We may not know the full impact of our interactions with others right away. We must be careful not to pass judgement too quickly.
Our prayer is for the Spirit to be working in the lives and hearts of the lost, that they can reach a point of conviction, and now convicted of sin they can find faith, hope, and love in Christ.