To keep the lamp alive,
With oil we fill the bowl;
'Tis water makes the willow thrive,
And grace that feeds the soul.

The Lord's unsparing hand
Supplies the living stream;
It is not at our own command,
But still derived from Him.

Beware of Peter's word,
Nor confidently say,
"I never will deny Thee, Lord," --
But, -- "Grant I never may."

Man's wisdom is to seek
His strength in God alone;
And e'en an angel would be weak,
Who trusted in his own.

Retreat beneath his wings,
And in His gace confide!
This more exalts the King of kings
Than all your works beside.

In Jesus is our store,
Grace issues from His throne;
Whoever says, "I want no more,"
Confesses he has done.

William Cowper

http://www.poemhunter.com/poem/dependence/