“No Pain, no gain” is a phrase that is frequently used in the pursuit of improving ourselves physically through vigorous exercise. It is understood that if our body does not hurt (some), we are not physically improving ourself. In emotional terms, it is a little different. In the example of striving to be nice, we are avoiding pain for the gain of improved relationships.
Avoiding pain
There is such a political divide lately, that seeking to change someone’s perspective could be extreme pain for some people. Many of us long for niceness in politics. CS Lewis noted in Mere Christianity that niceness is not going to save the world. Nevertheless, it is worth some meditation. There are clearly two sides to niceness – the giving side and the receiving side.
On the giving side of niceness, the contributor is seeking to be non-threatening, to provide what they think is the desired response that results in favor. On the receiving side of niceness, the receiver responds to what is being given. If the reception is good, ideally the receiver will respond in an expected way.
On being compliant
I have had occasion to be embroiled in unhealthy situations. I could have acted compliant and cooperative, but that does not assure a particular outcome. The receiving person may think I am being compliant to get what I want, and my actions are only a temporary facade. In that case, my niceness would be perceived as a non-believable ruse, and the effort would fail.
As a Christian, we live our daily lives with hope and attention to do God’s will. But, an experienced Christian will realize the human way of being nice is not part of what God wants from us. God did not become human to demonstrate ‘human-nice’. He became a human to provide redemption and to demonstrate his way to a new nice. We cannot learn God’s way of nice. It requires a radical transformation. We have to be changed from the inside out to experience His understanding of nice.
One of my favorite passages on this is Luke 9:23-24 which says “23 Then he said to them all: “Whoever wants to be my disciple must deny themselves and take up their cross daily and follow me. 24 For whoever wants to save their life will lose it, but whoever loses their life for me will save it.”
Radical transformation
The modern words, ‘radical transformation’, do not appear in this passage of course, but we discover that in the emotional context, pain for gain comes into play. My human idea of being nice for God is not what God wants. A human might have the concept of going from point A to point B, and the image that comes to mind is a walk or a ride to accomplish it.
There is nothing radical in that concept. However, if the human grows wings to move from point A to Point B, we have a radical transformation. This is the transformation God seeks when Jesus says “my disciple must deny themselves and take up their cross daily and follow me.” It is not enough to be nice. we have to be radical about living. After all, living for God is not about what I think about being a Christian. It is about being the creature God wants us to be. It is a perspective totally outside myself.
Some people may think that a radical life can only be lived if we set aside our lives from the world in order to pursue God. This does not mean we need to become a monk or a nun. 
Indeed, some may be called to this way of life, but it is not the calling of everyone. We can be set aside to live for God in a radically transformed way, without being separate from the world.
The true meaning of denying self and taking up one’s cross is radical. It requires that we need to stop thinking as we used to think, and instead put on the attitude of Christ in our daily living. 
Sometimes this will mean pain. Usually the pain will not be physical. It will be emotional or spiritual. At least, the pain is something we should welcome rather than avoid, since it is transformative and helpful to make us into something way better than we could ever expect.
