In the Sermon on the Mount Jesus addressed common ways that people often practice their righteousness before men: almsgiving, praying, and fasting. There is a way to do any or all of them that misses out on reward from our Father in heaven. After introducing the theme (Matthew 6:1), there are three subjects in four paragraphs, with prayer being the focus of two of them. If we associate prayer with fasting, which we should, then prayer gets a supermajority of attention.
Not only does prayer get Jesus’ attention, His warning and instruction about prayer is also based on a big assumption. Jesus makes a distinction between men who pray seeking reward from men and men who pray seeking reward from God. He does not mention those who don’t pray at all; that’s not an option. He assumes that we’re praying; even hypocrites and unbelieving Gentiles pray.
Hypocrites love to put on a prayer show for men. Gentiles need to pray a lot because their gods get busy and are not entirely reliable, so the more words the better chances of being heard. This performance is before a different audience but it’s still a show.
What does it say about us when we don’t pray at all, or at least in such a way that it could be assumed? It says we don’t understand righteousness, we don’t know the Father, and we don’t care about receiving a reward from Him. A prayer-less life won’t remain a secret, and it’s a sin we should confess.