And so to you, dear reader, I offer the same advice for your friend today:  “DANGER!”

Dabbling in dating relationships with non-Christians is like playing with fire.  It is not harmless, and you will get burned (whether you feel it or not).  I speak from personal experience, and I also speak as a friend who has seen other friends slide quite easily down this slippery slope. 

Even if you choose to skip over the entire book of 2 Corinthians in your Bible, no one can deny that chapter 6, verses 14-16, is ultra clear on this subject matter:

Do not be yoked together with unbelievers.  For what do righteousness and wickedness have in common?  Or what fellowship can light have with darkness?  What harmony is there between Christ and Belial?  What does a believer have in common with an unbeliever?  What agreement is there between the temple of God and idols?  For we are the temple of the living God.  As God has said:  “I will live with them and walk among them, and I will be their God, and they will be my people. 

So, in essence, don’t even go there.  Don’t even strike a match.  Step away from the matchbox.  “Danger, fellow Christian!  DANGER!” 

Sure, we all understand this and know that God has set up these unequally-yoked perimeters to protect his children.  But that doesn’t mean that it is easy for us to follow these instructions (2 Corinthians 10:5). 

Apart from Christ, the heart wants what the heart wants.  It can easily deceive us (Jeremiah 17:9), and we are wont to rationalize circumstances into what we want them to be and to fit our agendas.  The world says, “You can’t help who you fall in love with.”  But the Bible says, “Um, yes you can” (Titus 2:11-14).

This seems to be what is going on with your friend right now.  She wants what she wants and what feels good.  But she knows that it is not right (hence, hiding the fact that she’s dating a non-Christian).  At this point, her heart may also be hooked and she may think she’s in love.  She is deceiving herself, and when we don’t want to let go of something then it is very hard to walk away from it.

On a related note, you ask just how close a Christian should become with a non-Christian.  I think that is debatable.  Each person knows when their heart has gotten involved beyond a platonic level.  If a man and woman truly only feel friendship toward one another (like a brother and a sister), then friendship should be an option (and also seen as an opportunity for outreach and witness).  But if the Christian sees that this friendship with a non-Christian is pulling him or her away from Christ, then it’s time to reassess the nature of the relationship and establish some safeguards.