He who rescued us from so deadly a peril will continue to rescue us; on him we have set our hope that he will rescue us again, as you also join in helping us by your prayers, so that many will give thanks on our behalf for the blessing granted us through the prayers of many.2 Corinthians 1:10–11 (NRSV)
If you ever wonder whether your prayers make any difference, read this passage again.
Paul says that he is confidence in God to continue to rescue him from peril, but he also mentions that the Corinthian church is helping him by praying.
God is the one helping, not really the person praying. But God is responsive to the prayers of his people.
This is a great treasure for me at this stage of my life when, often, all I can do is pray. I helps me to know I am helping you when I pray for you.