Because God says so!

 

Write this down, for these words are trustworthy and true: To the thirsty I will give water without cost from the spring of the water of life - freely, as a gift. (Revelation 21:5-6)

 

T

 Then the Lord answered me and said:

Write the vision
And make it plain on tablets,
That he may run who reads it.
For the vision is yet for an appointed time;
But at the end it will speak, and it will not lie.
Though it tarries, wait for it;
Because it will surely come,
It will not tarry."

(Habakkuk 2:2-3, NKJV)

As you hope in Me I will renew your strength. You will soar on wings like eagles; you will run and not grow weary, you will walk and not be faint. (Isaiah 40:31)