The motto was correct but the type of love possessed by the pagan world was inadequate. No mere affection could overcome everything because emotions are always variable and affected by external circumstances. The love of Gad was something which could be, and was manifested.
Life is dependent upon love.
That which was manifested can be perceived. The manifestation was God's part, the perception is ours. A brother is worth more than my life. Indeed, Jesus teaches that it is better not to live than not to love. Love for others is the foundation of the Christian system.