Friendship involves three foundational elements, commitment to fulfill the responsibility of a friend, care and concern for the welfare of your friend, and affection.
This liking involves a "friendship kind of" affection based often on personality and common likes and interests.
A second kind of relationship is “brother-sister in Christ.” If we have accepted Christ as our Savior we have become children of God.
Gen. says, "For this reason a man will leave his father and mother and be united to his wife, and they will become one flesh." This verse tells us that marriage involves the husband and wife severing ties of intimate relationships with parents to cleave to each other.
It involves coming together into a permanent bond of unity.
However, the Bible does describe three kinds of relationships with the opposite sex and gives certain characteristics of each relationship (there are others such as parent/child and sibling, but they don't clarify the issues of dating).