Christians should never lie to one another. The devil's a liar ... there's no lying by God. He can't lie, He won't lie.
Adultery is a big one because there are as many divorces in the Christian community now as there are in the world. When you're married, your wife is your other half. There are blessings and intimacy between the both of you ... not with you and your neighbor's wife. You should be intimate with your wife only ... she is part of your covenant.
The sins mentioned here (and in a couple other previous articles) are carryovers from lifestyles of the world. Maybe some of us were into them before becoming Christians, but we haven't yet dealt with them. This is dangerous ... especially if we try to justify our actions.
The Fruit of the Spirit ties into this. When you "agape love" another Christian, you will not want to steal his wife. This is part of the Presence of the Lord in our life and the revelation knowlege of that Truth in which we walk.
Reverend Robert W. & Mary C. Butler