He wants us to show concern and pray about it, be specific about it. If you really believe every prayer is heard and answered. You have to visualize the people you are praying for, and ask the Lord to do this or that for them. The very intensity with which you pray is reflected in the answer!
Prayer is sort of like turning on a switch, it takes effort, but once the switch is flipped the current is on. In some cases it may take years to get the answer, but it will come. It's like in billiards; all the balls have to be lined up for the shot to work.
Also, alot depends on the recipient of your prayers. You've got to be in the right position and he has to be in the right position. If there is sin, or you are not tuned in right,or on the wrong channel, it won't work. It's like the radio; both the transmitter and the receiver have to be in tune for the signal to get through.
There are alot of factors which affect the whole process of prayer. Which is why you don't always get the answer right away. It may be you, or not God's time, or there may be a problem at the other end. So prayer depends on three principle factors; your position, God's position and the position of the other person for whom you are praying.
You've got to wait 'till it's God's time,and if you wait on God's time, and shoot straight you'll get the right answer!