"I have never known a person sweat blood; but I have known a
person pray till the blood started from his nose. And I have known
persons to pray till they were all wet with perspiration, in the
coldest weather in winter. I have known persons pray for hours, till
their strength was all exhausted with the agony of their minds.
Such prayers prevailed with God." – Charles G. Finney

"The main lesson about prayer is just this: Do it! Do it! Do it! You
want to be taught to pray. My answer is pray and never faint, and
then you shall never fail. There is no peradventure. You cannot fail....
A sense of real want is at the very root of prayer." - John Laidlaw

"Satan strikes either at the root of faith or at the root of diligence."
- John Livingstone

"A man who is intimate with God will never be intimidated by men."
– Leonard Ravenhill

"When God is about to give His people the expected good, He
pours out a Spirit of prayer, and it is a good sign that He is coming
towards them in mercy. Then when you see the expected end
approaching, then you shall call upon Me. Note, promises are
given not to supersede, but to quicken and encourage prayer: and
when deliverance is coming we must by prayer go forth to meet it.
When Daniel understood the 70 years were near expiring, then he
set his face with more fervency than ever to seek the Lord
(Dan. 9:2, 3)." - Matthew Henry

"God never denied that soul anything that went as far as heaven to
ask for it." - John Trapp

"So I sought for a man among them who would make a wall, and
stand in the gap before Me on behalf of the land, that I should not
destroy it; but I found no one." - Ezekiel 22:30

"When we go to God by prayer, the devil knows we go to fetch
strength against him, and therefore he opposeth us all he can."
- Richard Sibbes

"It will never be altogether well with us till we convert the universe
into a prayer room, and continue in the Spirit as we go from place
to place." - George Bowen

"God is presently seeking for a humble, praying people that He
can pour His glory through. If we will not yield to the Holy Spirit in
humble obedience, He will find a people who will! Some of us may
have to visit someone else's fellowship in order to experience the
coming move of God. Let's not deceive ourselves, God is not
committed to use us, but He is committed to remember the prayer
of the humble. (Psa. 9:12). If we refuse to prescribe to the Christ
honored methods of humility and prayer, we will certainly be
refused for the Master's use in the coming revival." - David Smithers