what does the bible say?

In one account it says, “Again the anger of the LORD was aroused against Israel, and He moved David against them to say, ‘Go, number Israel and Judah’” (2 Samuel 24:1).  In the other account it says, “Now Satan stood up against Israel, and moved David to number Israel” (1 Chronicles 21:1). How do we reconcile these two verses?

God was angry with Israel.  The only reason God is ever angry with any people is because they are committing sins.  Sin has its consequences.  To deter the whole of Israel from continuing in this law breaking, God decided to send corrective punishment upon them for their own good.  We see examples of this time after time throughout ancient Israel’s history. How, and by what method, did God correct Israel in this case?  By allowing Satan to test or provoke David to number Israel and take census of his soldiers.  

Of course, it is not wrong to take a census (see the book of Numbers).  However, David’s purpose for taking the census was to see how many soldiers he had for reasons of national security.  David, at this juncture, was relying on strength in numbers for protection and not on God! David normally placed his trust in God for his safety and protection, but this time David allowed Satan the devil to influence him to rely on mere numbers, and it cost him and the nation dearly.  Of course, he later repented and trusted God more than ever before.

God allowed Satan to test David.  David failed the test and sinned.  God did not force David to make an unwise decision (James 13-15).  If David had made the right decision, he could have been used to turn the nation back God.  Instead the nation had to suffer a plague to get their attention.