We often talk about love being the colour red. e.g. Love is like a red, red rose etc; we give red roses to show our love for others.
On the very first Easter when Christ was crucified, love has never been so red when His blood flowed freely for us.
But if we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus, his Son, purifies us from all sin. ~ 1 John 1:7 (NIV)
