The twelve words of Modeh Ani are the first prayer uttered in the morning. They thank God for restoring our life and soul to us at the dawn of a new day. The words of Modeh Ani do not contain any name of God, which means that we can say Modeh Ani i immediately on opening our eyes, without needing to first get up and wash our hands.
The prayer is apparently quite recent. Its first recorded mention is in a late 16th-century commentary on the siddur by the Safed kabbalist, Rabbi Ibn Makhir. But saying it daily has been adopted almost universally.
The words of Modeh Ani say "I thank you, living King that you have returned to me my soul in mercy - great is your faithfulness." The final words might appear to have been tacked on as an afterthought. What faith are we talking about?
It is God's faith in us that we are acknowledging. David Ben Yosef writes ofModeh Ani in his little classic, Is there a Chance for Love? "Your faith in me is very great. It seems that my mission in life has not yet been accomplished." On waking up, we acknowledge God's continuing faith in us to fulfil our purposes in the world.