The JWs maintain that the Bible sanctions “Theocratic War“:
So in time of spiritual warfare it is proper to misdirect the enemy by hiding the truth. It is done unselfishly; it does not harm anyone; on the contrary, it does much good. Today God’s servants are engaged in a warfare, a spiritual, theocratic warfare, a warfare ordered by God against wicked spirit forces and against false teachings. God’s servants are sent forth as sheep among wolves and therefore need to exercise the extreme caution of serpents so as to protect properly the interests of God’s Kingdom
Note that this is very similar in concept to the Islamic concept of Taqiyya, where Muslims may conceal their faith, or details about their faith, when they are under threat, persecution, or compulsion (and Muslims also believe in the Bible to a degree).
The justification offered by the JWs consists of the stories of Abraham, Isaac, Jacob, Rahab, the Gibeonites, David, and Elisha, all of whom told various forms of mistruth our outright lies without direct censure from God.
As a starting observation, Abraham, Issac, Jacob, the Gibeonites, and David all got into various forms of trouble for their lies. Not examples for us to emulate.
Rahab’s case is more interesting:
Rahab had taken the two men and hidden them. And she said, “True, the men came to me, but I did not know where they were from. And when the gate was about to be closed at dark, the men went out. I do not know where the men went. Pursue them quickly, for you will overtake them.” (Josh 2:4-5)
This is definitely an outright lie, and Rahab was clearly rewarded for her faith in taking the side of the Israelites – but this is not the same as being rewarded for her lies.
Elisha’s case is somewhat similar. An armed force came seeking him personally:
And when the Syrians came down against him, Elisha prayed to the LORD and said, “Please strike this people with blindness.” So he struck them with blindness in accordance with the prayer of Elisha. And Elisha said to them, “This is not the way, and this is not the city. Follow me, and I will bring you to the man whom you seek.” And he led them to Samaria. As soon as they entered Samaria, Elisha said, “O LORD, open the eyes of these men, that they may see.” So the LORD opened their eyes and they saw, and behold, they were in the midst of Samaria. (2 Kings 6:18-20)
Elisha did lie. (There’s an interesting counterpoint to this, what happened to Gehazi when he lied – 2 Kings 5 : 22- 27)
Do these examples justify us lying? No, because the New Testament gives Jesus’ disciples clear instructions:
I write to you, not because you do not know the truth, but because you know it, and because no lie is of the truth. (1Jn 2:21)
And the redeemed of the lamb are described like this:
These have been redeemed from mankind as firstfruits for God and the Lamb, and in their mouth no lie was found, for they are blameless.(Rev 14:4-5)