I think the Lord answers so many prayers and we are not aware of it. We may have moved on to the next prayer. Sometimes it's only when a biggie is answered, we are still and think wow - He answered this prayer and this prayer - wow, I didn't even realized this one was answered.
On the other side of the scale we may think He never answers prayer. We think about our child dying or the death of a spouse or friend, the loss of a job, etc.
I personally think God answers all prayer and to put it simply - the answer is yes, no, or wait.
A few weeks ago, I posted a prayer to pray against drug cartels and their destruction in Mexico. Saturday I was reading the newspaper and there was an article about the Mexican Navy arresting the crew of a submarine headed toward Mexico. The submarine was loaded with cocaine which was to be distributed through out the USA via Mexico. 2000 people have been killed this year in Mexico due to warfare between the cartels in Mexico. Most of the 2000 people are involved in the drug trade, but not all of them.
Out of those 2000, it's safe to say most of them never knew Jesus or His Father. I will keep praying especially as the violence spills over into the US. There are cities in Texas and AZ which are dangerous due to the drug trade. It's spreading like a cancer.
I will keep praying in faith because I know our Heavenly Father wants all people saved. He does not want to lose even 1 person. We may be the only people praying for the cartel members.
In Luke 15, we find these words Jesus spoke:
Then Jesus told them this parable: "Suppose one of you has a hundred sheep and loses one of them. Does he not leave the ninety-nine in the open country and go after the lost sheep until he finds it? And when he finds it, he joyfully puts it on his shoulders and goes home. Then he calls his friends and neighbors together and says, 'Rejoice with me; I have found my lost sheep.' I tell you that in the same way there will be more rejoicing in heaven over one sinner who repents than over ninety-nine righteous persons who do not need to repent.