Let us not love in word or talk, but in deed and in truth. 1 John 3:18
What John was basically saying here is that talk is cheap. Love is an action. We serve others sacrificially because we love them. Jesus loved us so much that He died on the cross for us and He wants us to love each other as He loved us.
Throughout my childhood my dad demonstrated a wonderful example of loving like Jesus, although I didn't understand it back then. He worked long, hard hours in a factory Monday-Friday. Every day he arrived home sweaty and exhausted. If I were him, I'd have spent Saturdays doing absolutely nothing.
My dad had a different agenda though. On many Saturdays, instead of sleeping in, he was up at the crack of dawn to spend the day at his aunt's house mowing the lawn, pulling weeds, trimming bushes, painting whatever needed painting and fixing whatever needed fixing.
My great aunt could have paid someone to do the work for her. She was willing, but my dad wouldn't have it. I never understood why he sacrificed his Saturdays until I started working on my relationship with God and started praying for Him to give me a heart more like Jesus. Now my dad's choice makes perfect sense to me...he loved his aunt by serving her, just as Jesus does for us.