the right order

Lewis puts the words in the right order.

Love - Love comes first, setting the attitude of the heart toward the things that are really important in life. If my actions come from a heart full of hate or indifference, I can't see how I'll have any chance of making a positive impact on the world around me. It means that I first take stock of what's really important in life, and put first things first.

Think - Using the mind comes next, employing our mental powers to the best of our abilities. In coming after Love, we have already put first things first and the abilities of reason and thoughtfulness are directed at things that really matter. It is perfectly easy, if Think comes first, to rationalize all kinds of behavior that is self-centered. But when it takes it's place as second behind Love, the mind can arrive at solutions that will genuinely do good.

Speak - Finally comes action, and the hope is that if we've fixed the heart and mind on the things that matter, then hopefully the body will follow. Our actions then, taking place in the context of a loving heart and a thinking mind, will have a chance to really make a difference for good.