We are all getting older and weaker

[TheGloryLand]

The tree that is growing, shed its leaves for many years, dry out and die. We need to do what we can do, while we can do it. What Bible verses can you apply to this saying, thank you.   

[BrotherTony]

Though in principle some of this is true...would you explain something like the Sequoia that has lived over 4000 yrs? Or the other trees that have lived to be thousands of years old around the world and seem to still be going strong? The Bible talks about our lives being like a blade of "grass" that withers and fades. 

1 Peter 1:24  For All flesh is as grass, And all the glory of man as the flower of grass. The grass withereth, and the flower thereof falleth away:

[TheGloryLand]

Isa.1

1. [30] For ye shall be as an oak whose leaf fadeth, and as a garden that hath no water.

[TheGloryLand]

sa.64

1. [6] But we are all as an unclean thing, and all our righteousnesses are as filthy rags; and we all do fade as a leaf; and our iniquities, like the wind, have taken us away.

[HappyChristian]

Leaves aren't trees. Just saying. lol

The thought behind your OP is right, though. Every growing thing on the earth eventually dies.

"So teach us to number our days, that we may apply our hearts to wisdom." Psalm 90:12

“I must work the works of him that sent me, while it is day: the night cometh, when no man can work." John 9:4  It seems Jesus agrees that there comes a time when no work can be done.