Updated: Jan 10, 2022
Many times, in prayer, we ask of The Lord what he is not able to do for us because we are also not willing to do the same for others.
Remember the bible says:
Psalms 66:17-18 The Living Bible Translation
 For I cried to him for help with praises ready on my tongue.
 He would not have listened if I had not confessed my sins.
That means if you have sin in your heart, The Lord will not hear or answer your prayers. If you want God to hear and answer your prayers, you must confess your sins to God and ask for mercy and forgiveness but it is important to know that forgiveness from God, is not automatic. Before you gain forgiveness from God, you must forgive everyone who has offended you weather they are right or wrong.
Mark 11:25 The living bible translation
 But when you are praying, first forgive anyone you are holding a grudge against, so that your Father in heaven will forgive you your sins too.
When people offend you, you have to let it go. It is not your place to avenge, it is not your place to pay them back in their own coin. If you hold hurt, offense, anger, and unforgiveness towards anyone. The bible is clear on the consequences. God will not forgive you for your sins, meaning He will also not hear your prayer no matter how long or how loud you pray. You have to free your heart from any sought of offense or vengeful feeling towards anyone.
Romans 12:17-21 The living bible translation
 Never pay back evil for evil. Do things in such a way that everyone can see you are honest clear through.
 Don’t quarrel with anyone. Be at peace with everyone, just as much as possible.
 Dear friends, never avenge yourselves. Leave that to God, for he has said that he will repay those who deserve it. Don’t take the law into your own hands.
 Instead, feed your enemy if he is hungry. If he is thirsty give him something to drink and you will be “heaping coals of fire on his head.” In other words, he will feel ashamed of himself for what he has done to you.
 Don’t let evil get the upper hand, but conquer evil by doing good.
Ok so what if the person has really hurt you terribly and you're trying your best to forgive and let go, but you just can't? That's where the help of the Holy Spirit comes in. Tell the Holy spirit that you want to forgive but you can't. Ask him to please help you forgive and let go. See what the bible says about the holy spirit and the love of God in your heart.
Romans 5:5 The Living Bible Translation
 Then, when that happens, we are able to hold our heads high no matter what happens and know that all is well, for we know how dearly God loves us, and we feel this warm love everywhere within us because God has given us the Holy Spirit to fill our hearts with his love.
Another key to letting of offense and hurt is to start praying for the person who has hurt you and you will find out that like wax, the hurt and pain will melt away. Leaving free and relieved in your soul.