16 As for me, I call to God,
and the Lord saves me.
17 Evening, morning and noon
I cry out in distress,
and he hears my voice.
18 He rescues me unharmed
from the battle waged against me,
even though many oppose me.
19 God, who is enthroned from of old,
who does not change--
he will hear them and humble them,
because they have no fear of God. 
David, the warrior poet, wrote this Psalm and he might have been referencing 2 Samuel 15-18 when Absalom (David’s son) put together a coup in an effort take the throne. There are some parts of this Psalm that might not fit that scenario, but regardless, David was feeling the pressure of his enemy. Further, this enemy appears to be someone who David was once close to.
In verse 2 David admits that he is distraught because of this betrayal. So he appeals to God in prayer and asks that God would not ignore his plea. Life is not going well for David so he turns to God. I would encourage you to read the entire Psalm and listen not just to the words, but the hurt, pain, and sorrow behind the words. David prays against his enemy, in fact, he prays for enemies to die and go to hell (v. 15). That seems extreme, inappropriate, and maybe even sinful from our perspective.
C.S. Lewis wrote a book titled Letters to Malcom a fictitious interlocutor on the topic of prayer. As usual Lewis offers great insight and thoughtfulness to the topic. Our prayers are often not going to be clear, easy, or even pure. By that I mean that prayer is often where unfiltered emotion surfaces. It is the place where it is okay to not get everything just right. Lewis puts it this way, “We must lay before Him what is in us, not what ought to be in us.” Perhaps that is what David is doing in Psalm 55.
Nevertheless, in verse 16 David says, “as for me, I call to God…” Will you do that when times are tough, when you don’t know what to do, when you are at the proverbial end of the rope. Will you appeal to God? It’s okay to be desperate and in that state turn to God. That is exactly what we should do.
What do you need bring to God today? What are you struggling with in life? Are you struggling loving your wife, husband, son, daughter, mom, dad…? Are you desperate about a financial situation? Are you desperate because a friend betrayed you? Is there someone you need to forgive? Is that person you? Lay it before God and let Him begin to work!
 The New International Version (Grand Rapids, MI: Zondervan, 2011), Ps 55:16–19.