Is Blood Really Thicker Than Water?

Continuing on in Romans 12 the next phrase is

Romans 12:10 Be devoted to one another in brotherly love.

The saying “blood is thicker than water” commonly means that our relationships with our blood relatives demand more loyalty than any of our other relationships.   Some Christians have tried to redeem this phrase by making it mean just the opposite.  They would like it to mean that the blood of the covenant is thicker than the water of the womb.  The bonds formed between brothers and sisters in Christ are thicker than the bonds between those who are born of the same womb.  It’s probably a lost cause to try to force this meaning upon the words.   Better just to reject the worldly proverb and insist that blood is not thicker than water.  Rather, the unity we have in the waters of baptism (in the union with Christ therein symbolized) is a real spiritual unity and it is of greater value and significance and permanence than our connection to blood relatives.

So when Paul tells us to be devoted to one another in brotherly love, he’s not saying that we should act as if we are brothers and sisters in Christ.  No pretending is required.  We really are brothers and sisters and as brothers and sisters we are to be, in the Greek, philostorgoi toward one another. 

The word philostorgoi refers to familial devotion and affection.  The word “astorgoi” is used in Romans 1:31 and 2 Tim 3:3 and is translated “heartless”.  So we are to love one another from the heart.

1 Peter 1:22 Now that you have purified yourselves by obeying the truth so that you have sincere love for your brothers, love one another deeply, from the heart.