Be wise in the way you act toward outsiders; make the most of every opportunity. Let your conversation be always full of grace, seasoned with salt, so that you may know how to answer everyone. (Colossians 4:5–6, NIV 1984).
My Musings – Be wise, because not every interaction with a non-believer will be an opportunity to share the Gospel. Introducing the Gospel at an inopportune time, could do more damage than good. So, be open to the prompting of the Holy Spirit, and allow Him to guide you into how (and when) to answer. Giving an answer implies that the question was raised, or an opening was given, by the non-believer. Don’t force it. Show grace. Favor to the unworthy, because we were once so. Seasoned. Not to give flavor to that which is lacking, or obscure its true “tastefulness,” but to bring out its natural flavor.
My Advice – Above all, you need to know the answer. Not just the what, but also the why.