“But also for this very reason, giving all diligence, add to your faith virtue, to virtue knowledge, to knowledge self-control, to self-control perseverance, to perseverance godliness . . 2 Peter 1:5-6
The Greek word for godliness is sometimes translated as piety. Both words have become obscure in their meanings, due to lack of use. Godliness means to continue to believe and serve God above all else, because He is God. 2 Peter 1:6 tells us to add godliness to perseverance because godliness is born out of persevering. Trials eventually bring the child of God to a point where he or she has to choose whether or not to continue believing and serving God. A positive attitude has its limit. When that limit is reached, then we are mentally forced to choose between two attitudes:
1. God has disappeared from my life, and I give up (faith, service, etc.)
2. I will serve God because He is God, regardless of my circumstances.
The flesh, suffering under trial, urges the second choice. The flesh expects to be rewarded for its labors. When we labor for God and are not rewarded, we become frustrated. When we choose to serve God, solely because He is God; expecting no fleshly reward, then we have added godliness to our lives. Godliness is a choice of faith, apart from any external evidence. Job is an excellent example of one who chose to serve God after being stripped of everything.
Here is an example which illustrates the development of godliness on the human level. Years ago, my oldest daughter asked to have her own room. She shared a room with her younger sister, and we had an extra room. I promised her she would receive her own room when she learned to keep her room clean. After several months, she finally gave up the idea of getting me to cave in for nothing, and cleaned her room. She came to me expectantly and told me her room was clean, and reminded me of my promise. I told her to continue her cleanliness, and then I would give it to her. Her first response was that I was being unfair. I reminded her that keeping her room clean involved time, not a one time shot.
Now, for the sake of illustration, let's assume that after another three months of faithfully cleaning her room, I gave her the same response. And again a year later, I give her the same response. Let's assume that I have secretly chosen a date three years down the road. After the first year or two, she will become frustrated in her efforts. At some point, she will lose sight of having her own room and have to make a choice. She will choose to give up and let her room get messy, or she will choose to continue cleaning her room because she knows that is her father's will. If she chooses to keep on cleaning, then has she added a form of (earthly) godliness.
So it is with us. We either serve God for blessings, or because He is God. When we add godliness to our lives, we are making that choice where we will serve God because we want to please Him.