"....And he went a little farther, and fell on his face, and prayed, saying, O my Father, if it be possible, let this cup pass from me; nevertheless not as I will, but as thou wilt..."
"....For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men,......"
We live under judgement. We live in a sin stained enviroment.
The world is our whole existence, as it has been, and is, conditioned by sin...As we see it , the world is the world of time and of things, in which nature and spirit, body and soul, the ideal and the material, interact and oppose one another. It is a world in which things move towards independence, a world of things existing powerfully in their own right, a world of principalities and powers and thrones and dominations. Like men, the world is imprisoned. As their world, it unwillingly participates in the perversity of men and shares their damaged relationship with God [Barth]
Through sin, death entered into the world. Death is the supreme law of this world, but it also points to a Lawgiver. Death is judgement, barrier and exit, end and beginning, the Divine 'No' and 'Yes', the visible sign of the wrath of G-D, it is the divine command Stop.
Through sin, perversions such as the example you have provided occur on a daily basis, whether in the Church, or school, or sadly yet, in the home. We are infected through and through.
So, what prayer shall we pray? Shall we pray that a persecution be stopped today, that an evil thrown against us should cease today? Shall we pray that we have food to eat today, or that our monetary provisions should increase today ? Or that a physical assault shall end immediately ? Absolutely YES to all, and we are commanded to bring our supplications to our Heavenly Father.
But what of tomorrow ? Or the next day and the next year ? We shall still be stained by our sins and inhabiting a fallen enviroment that assaults us until we run into the Divine barrier to our sin, which is death.
The ultimate answer to any and all prayer, has been given already. It is the death that ends death. It is the redemptive work of Christ. So, is G-D a liar as you have asked ? I say that He has answered all prayers from all time, for there can be no greater request of prayer than to be saved from ourselves.
"..So then as by the offence of one judgement came unto all men to condemnation; even so by the righteousness of one the free gift came unto all men to justification of life. For as by one man's disobedience the many were made sinners, so by the obedience of one shall many be righteous..."