Have you ever pestered someone long enough that they finally gave you what you wanted just to shut you up? My grand daughter does it to me all the time. She'll have her mind made up about something and she won't let up until I finally give in and give her what she wants. It drives me nuts... but hey, it's works. Sometimes the battle's just not worth the fight and unless it's worth standing my ground on... I'll usually give in (Yes, I'm a Grandpa!)
In Luke 18:1-8, There's an example of a woman that constantly went to an unjust judge asking for protection from her opponent. She bothered this judge so much with repeated pressure that he finally said to himself, "I better give her what she wants or she'll wear me out!" Again, reminds me of my grand daughter.
This passage of scripture gives all of us great hope. If an unjust judge gave into this woman's pressure because of her constant efforts, well how much more would a just God react to the requests and prayers from those he loves? Much more of course! So it's not that we should pester God with our prayer requests over and over thinking we'll wear him out and he'll finally give in to us. But instead know that God loves you and will answer you when it's right for you. Maybe He's teaching you about faith or patience or hope. But know this... God hears you and loves you and will answer you in His time for His purpose and for your benefit.
Stay the course... pray continually while trusting in God to answer. We should always pray and never lose heart.