SAND: BILLIONS OF TINY ROCKS

"Therefore whosoever heareth these sayings of Mine, and doeth them, I will liken him unto a wise man, which built his house upon a rock:  and the rain descended, and the floods came, and the winds blew, and beat upon that house; and it fell not: for it was founded upon a rock.  And every one that heareth these sayings of Mine, and doeth them not, shall be likened unto a foolish man, which built his house upon the sand:  and the rain descended, and the floods came, and the winds blew, and beat upon that house; and it fell: and great was the fall of it" (Mt. 7:24-27).

The two verbs, "doeth" in verse 24, and "doeth" in verse 26, are translated from the same Greek word, ποιέω, but they differ in two ways:  
     [1] The first and most obvious difference, ποιέω in verse 26, also contains μή, a word which shows the action does not happen.
     [2] the other difference, less obvious but extremely important for our proper understanding of what Jesus was teaching, is the fact that in verse 24, ποιέω is a present, active, indicative, while in verse 26, ποιέω is a present, active, participle. 

The Greek present, active, indicative is a simple statement of fact.  The action occurs just once, either presently, in the past, or will occur in the future.  With the case of the Greek present, active, participle, the participle corresponds with the English participle, adding the suffix "-ing."  When a writer uses the participle, he does not envision an end of the action; it will go on and on indefinitely, or be repeated continuously; it is an open-ended action.
  
In other words, ποιέω with μή in verse 26, represents the "foolish man," who is continuously trying to find a basis for his salvation; but religion and the Law will not save him (Gal. 3:1-24).  It is the "wise man" who makes a decision, at some point in time, that affects the rest of his life:  trusting Jesus (Gal. 3:25-29)!  Jesus is the Rock upon which the saved man stands (Dan. 2:44-45; Rom. 9:33; 1 Cor. 3:11; 10:4; 1 Pet. 2:8; etc.)!

One can either trust in Jesus and rest in the knowledge he is a child of God, or he can continue to "find some footing" through religion and works of the Law:  seems like a no-brainer to me!