Be leery of spending too much time with unbelievers. It is much easier to pull someone into sin as the unbelievers may lead you than it is for you to pull an unbeliever to righteousness. While it is possible, it is unwise to allow yourself to be easily influenced by unbelievers. Just like the light is separate from the dark, we must also have clear boundaries.
And we pray:
Dear God, please give me wisdom about the friendships I develop here on Earth. Allow me to minister to others, but protect me from becoming joined together with unbelievers. Help me to avoid any influences that turn me away from You. May I live my life filled with Your light so that those living in darkness do not even try to pull me away from You, O Lord, I pray in Jesus’ name, Amen.