What Makes Satan Tremble?

I took the Bible Study at North Preston Evangelical Church last night, which was followed by their weekly prayer meeting. Prior to the prayer time, we sang a hymn by William Cowper. I do not recall singing it previously, though I was incredibly challenged by its words:

What various hindrances we meet
In coming to a mercy seat;
Yet who that knows the worth of prayer,
But wishes to be often there.

Prayer makes the darkened cloud withdraw,
Prayer climbs the ladder Jacob saw;
Gives exercise to faith and love,
Brings every blessing from above.

Restraining prayer, we cease to fight;
Prayer makes the Christian’s armour bright;
And Satan trembles, when he sees
The weakest saint upon his knees.

While Moses stood with arms spread wide,
Success was found on Israel’s side;
But when through weariness they failed,
That moment Amalek prevailed.

Have you no words? Ah, think again,
Words flow apace when you complain;
And fill your fellow creature’s ear
With the sad tale of all your care.

Were half the breath thus vainly spent,
To Heav’n in supplication sent;
Your cheerful song would oft’ner be,
“Hear what the Lord has done for me.”

The penultimate verse really convicted me. I'm a great one for complaining to others, yet my conversations with the Lord are often all too brief. Every verse offers a challenge to pray and pray again. Why are so many Christians feeble and stunted? They neglect the Word and ignore the Lord in prayer. Why are so many churches weak and lifeless? The saints neglect their prayer times. Why are so many pastors weary and tired? The people are busy complaining about him instead of interceding for him.

Forgive the brevity of this post, but I'm off to pray.