Ephesians 8:26 says, "In the same way, the Spirit helps us in our weakness. We do not know what we ought to pray for, but the Spirit himself intercedes for us through wordless groans."
I don't know about you, but this passage gives me hope. There are so many times I don't know what to pray. I am merely standing before God with my mouth open but no words coming out. During these times, I'm so thankful the Holy Spirit intercedes for me! What an amazing thought!
Consider these words from Bible scholar Robert Morgan. This is one of the best explanations of prayer and God's will that I have ever read!
We are weak in many ways, but in this passage the apostle Paul is specific about the particular weakness he is addressing—our prayer lives. We are weak when it comes to prayer. In what way? Well, we are weak in many ways, but here again Paul has something specific in mind. We are weak in our ability to know what we should ask. Many times we really don’t know what we should specifically pray for. We are not omniscient. We don’t know everything, nor can we see into the future. So we don’t know whether the things we’re asking for will turn out good or bad for us.
An old story illustrates: A Chinese gentleman lived on the border of China and Mongolia. In those days, there was constant conflict and strife along the perimeter. The man had a beautiful horse. One day, she leaped over the corral, raced down the road, crossed the border, and was captured by the Mongolians. His friends came to comfort him. “That’s bad news,” they said sadly. “What makes you think it’s bad news?” asked the Chinese gentleman. “Maybe it’s good news.” A few days later the mare came bolting into his corral, bringing with it a massive stallion. His friends crowded around. “That’s good news!” they cried. “What makes you think it’s good news?” he asked. “Maybe it is bad news.” Later, his son, while riding the stallion and trying to break it, was thrown off and broke his leg. “That’s bad news,” cried the friends. “What makes you think it is bad news?” asked the Chinese gentleman. “Maybe it’s good news.” One week later, war broke out with Mongolia, and a Chinese general came through, drafting all the young men. All later perished, except for the young man who couldn’t go because his leg was broken. The man said to his friends, “You see, the things you thought were bad turned out good; and the things you thought were good turned out bad.”
And thus it is with us. We don’t know if the things we want will really be good for us, or bad. We can’t see the future. That’s why James tells to us to pray, saying, “If it be thy will....” But God does know the future. He is Alpha and Omega, the First and the Last. He knows the end from the beginning, and He knows how all things will turn out. Verse 26 says that the Holy Spirit prays for us according to the will of God with intensity, with groanings that words cannot express. And God answers the Holy Spirit’s pleas on our behalf. The result is Romans 8:28! As the Holy Spirit prays for us, God answers His prayers, therefore all the things turn out for our good in the unfolding providence of the Lord. (Nelson's Annual Preacher's Sourcebook: 2002 edition. Nashville: Thomas Nelson Publishers)