2 Samuel 24:1 says, "Again the anger of the Lord was kindled against Israel, and he incited David against them, saying, 'Go, number Israel and Judah.'" The parallel passage in 1 Chronicles 21:1 says, "Then Satan stood against Israel and incited David to number Israel." The obvious difference between the two has provoked a great deal of discussion among the commentators and theologians. I have no intention of adding to the dispute about the Lord or Satan. Instead, I suggest a different alternative.
On the basis of this observation, I suggest that satan in 1 Chronicles 21:1 ought to be translated "an adversary." The significance is as follows. The Lord raised up an unnamed adversary against David. This adversary was probably not an individual, as in the cases with Solomon, but rather an army. The census that this adversary provoked David to take was a census to determine the strength of forces that David could call upon if the need arose. As 2 Samuel 24:1 says, "he incited David against them." The "them" is probably not Israel, but the adversary. This is a test for David. Will he trust in the power of the Lord to defeat this adversary, or will he rely on the strength of his army? It is similar to what the Lord says in Judges 2:221-23, "I will no longer drive out before them any of the nations that Joshua left when he died, in order to test Israel by them, whether they will take care to walk in the way of the Lord as their fathers did, or not.” So the Lord left those nations, not driving them out quickly, and he did not give them into the hand of Joshua." The Lord tested David, and in this case he failed, bringing judgment on the people as a whole, as did the sin of Achan in the taking of Jericho.