First:

Be kind to all strangers and not just the one's who spark your romantic interest. (Hebrews 13:2)

All strangers fall into one of the following categories. THEIR ARE NO EXCEPTIONS.  They are either a brother or sister in Christ, a soul in need of Salvation or a lost soul (back slidder) and in need of Restoration. (Galations 6:1)
Identify Strangers quickly. THEIR ARE NO OTHER POSSIBILITIES.
 
They are either saved or they are not. (1Corinthians 6:9-11) They either have a church home or affiliation or they do not. They either value Christian fellowship and assembly or they do not.(Hebrews 10:25, Colossians 3:16)
 
Identify them quickly. How you proceed seriously depends on how you classify them.
 
a. Brothers and Sisters in Christ are members of the Body of Christ, perhaps affiliated with another church other than your own.
b. A lost Souls in need of Salvation: People who have not yet accepted Christ as lord and Savior in their heart.
c. Reprobate Christians: Those who have accepted Christ at some point but have fallen out of fellowship with God and or their saving Church. They have no church home or affiliation. They do not live according to Christian values.
 
Other truths to consider:
You are an ambassador for Christ as well as your local church. (2 Corinthians 5:18,20), (Galations 1:10)
When you have no "romantic interest" in a person, God still has Kingdom Interest in everyone.
His kingdom interests for everyone "ought" to come before your romantic interest for anyone.

God's interests are more important than your own self interests. (Matthew 4:19,20)
Be not unequally yoked with non believers. (2 Corinthians 6:14)
 
Practical Application: Unequally Yoked (2 Cor 6:14-17)
1.Romantic relationships without meeting the other persons church family, or introducing them to yours are extremely risky .
2. Romantic relationships between you as a "saved" person and an "unsaved" person epitomizes unequally yoked.
3. Romantic involvement with "backsliders" and people out of fellowship or no church affiliation is not in your best interest.
 
Avoid the drama. Don't start no mess...won't be no mess!!!
 
Faith Family Values:
All romantic interests should come after soul salvation and out of Christian fellowship.

In other words, don't even think about coupling with someone until after the issues of soul salvation and church affiliation have been addressed.

If they have no church home or affiliation, insist that they visit your church before any other social activity takes place.

If they have a church home or affiliation, visit theirs before any other social activity takes place.

If they refuse to come into the fellowship with the body of Christ, draw a line in the sand. Only allow casual communication. IOW; if not limited to over the phone, in passing only, at school, work, or publicly.

Always be kind to strangers. 

Because you belong to Christ you at all times represent Him. (1 Corinthians 19-20)
 
Core Value: Do they know Jesus Christ in the pardoning of their sins? Are they in fellowship with other believers? These are the first and most important things to "get to know" about someone. 
 
These questions are more important than questions of astrological signs, loving the Lakers, job security, what car they drive, can they cook, or if they are married, ever been married, do they have any kids. WHERE WILL YOU SPEND ETERNITY? GET TO IT.
 
Even if you don't ask it first, DON'T BE DECEIVED . That is the most important thing to "GET TO KNOW."