Being deeply loved by someone gives you strength, while loving someone deeply gives you courage.
Lao Tzu

And now these three remain: faith, hope and love. But the greatest of these is love.
1 Corinthians 13:13

Where there is love there is life.
Mahatma Gandhi

The three grand essentials of happiness are:  Something to do, someone to love, and something to hope for.
Alexander Chalmers