God is love and has given us everything in our lives. The most appropriate response is to give everything back to him, including our very selves.
Here is a consecration prayer to the Trinity with this in mind, attributed to St. Francis de Sales.
I vow and consecrate to God
all that is in me:
my memory and my actions to God the Father;
my understanding and my words to God the Son;
my will and my thoughts to God the Holy Spirit.I consecrate my heart, my body,
my tongue, my senses and all my sorrows
to the sacred Humanity of Jesus Christ,
who consented to be betrayed
into the hands of wicked men
and to suffer the torment of the Cross for me.