I had a thought on this one. The Bible says,
Hebrews 4:12
For the word of God is quick, and powerful, and sharper than any twoedged sword, piercing even to the dividing asunder of soul and spirit, and of the joints and marrow, and is a discerner of the thoughts and intents of the heart.
Perhaps what is at issue isn't so much the deed... but the thoughts and intents of the heart. For example, if you lied to protect Jews from Nazis is not your "lie" a weapon to protect? Your intention was to protect and save lives from evil men.
Now, if you lied on your taxes that's a bigger issue. You see, government has the right to demand taxes and the Apostle Paul even admonishes Christians to pay their taxes (
Romans 13). If your family cannot afford food after paying taxes.... the question becomes, "Where is your church?" Every church should have the capability of providing food for needy families. If not, there are a number of food banks to turn to.
Anyway, those were a few of my thoughts.