1. Prayer is talking with God.
It’s easy to complicate prayer. There is a place for detailed, theologically-precise definitions of prayer. I could write a paragraph-length one that included most of the points found in this article. And while it might be a thorough and helpful explanation (more than a definition) of prayer, it wouldn’t be memorable. So while there is a lot of important biblical information to understand about prayer, at its essence prayer is simply talking with God.
2. Prayer is acceptable to God only in Jesus’s name.
All access to God—including prayer—is possible only through the merits of who Jesus is and what he has done. Jesus made this plain in John 14:6: “I am the way, and the truth, and the life. No one comes to the Father except through me.” But to pray “in Jesus’s name” is not accomplished simply by adding (often mindlessly) those words at the end of a prayer; rather, it is to pray with reliance on what Jesus has done for us and not the worthiness of who we are or what we have done. See also the emphasis made by Jesus on praying in his name in John 14:13 and John 16:23-24.