the one who exhorts, in his exhortation; the one who contributes, in generosity; the one who leads, with zeal; the one who does acts of mercy, with cheerfulness. (ESV)
Have you ever considered that doing acts of mercy is a spiritual gift? We should all be doing acts of mercy towards other, regardless of whether or not it is considered our gifting from the Lord. However, those who do have this spiritual gift are given extra admonition to do so with cheerfulness. There is a reason why the Apostle Paul includes these words.
The Apostle Paul was a Pharisee. The Pharisees were the religious leaders of the Jewish people. The Pharisees would have instructed the people to give "alms" to the poor and needy. Alms were gifts of food or money given to the poor. When the Pharisees gave alms they did not do so with cheerfulness, but with the intention of being seen by others.
God calls us to do acts of mercy. How we do these acts of mercy is just as important as the act itself. We are not to do things for the purpose of gaining glory for ourselves. If we do, we will not be exhibiting cheerfulness, but pride. God is always concerned about the attitude of our hearts. Our actions need to match our hearts.
The key to having a right attitude when it comes to giving away anything is answering the question of ownership. Who owns things. Do you have an accumulation of material possessions that you decide to give away? Or do you recognize that every single thing you have belongs to God and when he directs you to give it away, it is a simple act of obedience to give away what belongs to God.
We all will be called by God to do acts of mercy for others. Do not worry about getting credit or praise for what you are doing. If you want to honor God with a cheerful attitude start by recognizing that everything belongs to Him!