Being whole and complete in moral and ethical principles.
Read Job 1:13-2:10.
There are sixteen references in the Bible about integrity, and four of these occur in the book of Job describing his character. Job was a man who remained steadfast in his integrity in spite of the tests he faced.
Integrity comes from the Latin word integritas, which means wholeness, entireness or completeness. The root word "integer" is often used in math to represent a whole number, meaning untouched, intact and entire. Literally, integrity means you have a complete soul. It's not synonymous with ethical behavior, though ethics will often follow, but is more related to the whole concept of "being" rather than "doing." You don't attain true integrity through a series of behaviors (doing) but by being internally transformed through a personal relationship with Jesus.
God is into making integers; Satan is into fractions. God desires to bring people to wholeness, putting all the pieces together which will ultimately take place in heaven when we're united with Him. Satan, working through the vehicle of sin, tears things apart, dividing people and bring confusion and conflict. Remember, God's plan will ultimately succeed, and His universe will one day become one glorious integer (whole and complete). But until that happens, you and I must live in a fractional world and experience the problems that come from fragmentation.
Integrity must continually be built in our lives through the disciplines of our faith in Jesus Christ. We cannot place confidence in our own integrity and relax and become lazy, or we will soon regress into a pitiful state. Ted Engstrom said, "No matter how much we try to hide our actions, our integrity (or lack of it) always shows through." Integrity of character occurs when there is consistency between actions and inner convictions over time. Strong Christian character results from both human effort and divine intervention.