Prayer has an amazing effect in more ways than can be measured. The obvious effect is that heaven hears and moves in response to prayer. It is obvious throughout Scripture that we have the unexpected ability to move the gates of heaven and hell with our prayer. I say this is unexpected because who would have thought that God would have been interested in what we have to say? It really is quite unthinkable that we can sway such a powerful omnipotent being, who is holy and omniscient. Yet, there He is...and He is listening.
But a less than obvious effect is often the encouragement we feel just in knowing that another human being knows and is praying for us. This can be a very comforting thought. A dear friend Kate passed away several years ago. She was half blind and in bad health but, when I went in her house late in the evening sometimes, I could tell that the accumulated time that she had spent praying throughout the day had literally filled her living room with a glow, a living presence of the Spirit. It didn't seem that saturated earlier in the day when she was moving around doing chores, and feeding herself. But, in the evenings she sat in her chair and prayed, talking in tongues. In the evening, it was like the feeling of the Spirit was so thick you could "cut it with a knife" as the expression goes. I know I was comforted to know I was on her prayer list.