If His mercies are renewed every morning  - so too should our gratefullness for those mercies be renewed every morning. 

If His desire for us is new every morning, so too should our desire for Him be renewed every morning.

My wife wants to hear me say "I love you" every day we're together   - shouldn't we say this to God every day? Every time we're together?

Love is proactive.  Love notices our needs and moves to fulfill them before they arise   - our need for His mercies, our need for His love, is never-ending  - every morning of every day we need Him  - so every morning we should seek Him anew, for He is seeking us. I know He is with us always, He never leaves or forsakes us  - but, though I'm with my wife daily, she still wants me to pursue her, she wants to feel desired  - to show her with words and deeds, daily, that I love her. If I chose to meet with her once a week for a few hours, she'd probably divorce me.