"I will bless the Lord at all times; his praise shall continually be in my mouth." (Psalm 34:1 ESV)
To say I will bless the Lord on all occassions and unfailingly, and I will praise Him constantly without interruption is quite a commitment. I am saying I will bless the Lord whether the occassion is joyful or heartbreaking, and my praise to Him will not stop regardless of my circumstance.
I am also committing to this before I know what my future circumstances will be. It's easy for me to bless the Lord and praise Him after the fact, even after difficult circumstances, because I already know the end result. But how can I commit to blessing God and praising Him always and without interruption even though some of my future circumstances are sure to prove difficult? It is daunting because I am sure to fail. I doubt my ability to succeed in keeping my commitment.
But, it's not about knowing if I will succeed or fail. It's about the matters of my heart. I can say I will bless always and praise continually because my heart has been conditioned to do so. I look back and see where He's brought me from, and I have found myself to be thankful. I know the journey I've walked, so I know how different it could have been for me. I know my heart condition could have been disinclined towards Him.
I have not made myself thankful; He has made me thankful. Because He has made me thankful thus far, I can trust He will continue to make me thankful as long as I rely on Him through whatever comes my way. So, I commit to blessing Him always and praising Him without stopping no matter what because I am thankful. I am thankful to be thankful.