One thing that I have found that often goes neglected in a believers life is the discipline of prayer.
Prayer was designed by God. He is the one who came up with the whole concept in the first place. Prayer is meant to bring results. One reason that people don't pray is that they don't see the results of their prayers. Prayer is meant to be answered.
And in that day ye shall ask me nothing. Verily verily, I say unto you Whatsoever ye shall ask the Father in my name He will give it to you. Hitherto, have ye asked nothing in my name: ask, and ye shall recieve that your joy may be full - John 16: 23-24
If your prayers are not being answered there is no joy. God is telling us through the Word that when you receive the answer or manifestation of your prayer then your joy will be full. One of the ways you experience the joy of God is through answers to prayer.
If your prayers are not being answered then maybe it times to go back to the chalkboard and wipe it clean and see if there are some negative habits that you have picked up that are not working.
The first component in answered prayer is to ASK. I know that this may sound elementary but I have found out that one reason that people don't receive is that they never ask. You have not because you ask not.
What is it you need God to intervene in. Take prayer seriously. When you begin to see the manifestation of answered prayer you will begin to experience joy that comes from your heavenly Father.