I have looked careful over the lives of God’s saints in the Bible. I cannot find one whose history much is told, from Genesis to Revelation — who was not a person of prayer. I find it mentioned as a characteristic of the godly, that “they call on the Father,” that “they call upon the name of the Lord Jesus Christ.” I find it recorded as a characteristic of the wicked, that “they do not call upon the Lord” (1 Peter 1:17; 1 Corinthians 1:2; Psalm 14:4).
I have read the lives of many eminent Christians who have been on earth since the Bible days. Some of them, I see, were rich, and some poor. Some were learned, and some were unlearned. Some of them were Episcopalians, and some were Christians of other names. Some were Calvinists, and some were Arminians. Some have loved to use liturgy, and some to use none. But one thing, I see that they all had in common — they have all been people of prayer.
I have studied reports of missionary societies in our own times. I see with joy that lost men and women are receiving the gospel in various parts of the globe. There are conversions in Africa, in New Zealand, in India, in China. The people converted are naturally unlike one another in every respect. But one striking thing I observe at all the missionary stations — the converted people always pray.
I do not deny that a person may pray without heart and without sincerity. I do not for a moment pretend to say that the mere fact of a people praying, proves everything about their soul. As in every other part of religion, so also in this — there may be deception and hypocrisy.
But this I do say — that not praying is a clear proof that a person is not yet a true Christian. They cannot really feel their sins. They cannot love God. They cannot feel themselves a debtor to Christ. They cannot long after holiness. They cannot desire Heaven. They have yet to be born again. They have yet to be made a new creature. They may boast confidently of election, grace, faith, hope and knowledge, and deceive ignorant people. But you may rest assured it is all vain talk — if they do not pray.
J.C. Ryle, A Call to Prayer