Behind every action, there is intention. Sometimes, there can be many different intentions that lead to the same action. Therefore, while inwardly good decisions/thoughts will lead to outwardly good deeds, some good deeds are the result of inwardly bad decision. In lift, those who commit wrong usually can justify (to themselves mostly) their actions. We see this not only with criminals, but even when observing famous people (i.e. celebrities, politicians, etc.) or those around us (i.e. friends, colleagues, neighbours, bosses, etc.).
God looks at the heart. This means that as Christians, we need to do things with the right intentions. Take for example the reasons why Christians don't swear. Some may choose not to because they want to be seen as good Christians while others do it as to not stumble a fellow Christian or be a good testimony to the world. In a way, the former are like the Pharisees that Jesus called hypocrites. The latter does it because they love God.
In the bigger picture, the question that most (if not all) of us keep asking is, "What is my purpose in life?" Is it to do well in our studies? Or perhaps it is to chase worldly success? Others may make it their life goal to earn wealth. There is also some who simply want to enjoy life and be happy always. There are also those who want to live a legacy or advance a cause. At the end of the day, our lives are our own to decide what to make of it.
The problem with chasing worldly purpose is that it is never enough. The satisfaction we get from it is temporal at best. In short, we all have a God-shaped hole in our heart that can not be filled with the things of the world. It is only when we seek after God that we find fulfillment that satisfies. Jesus told the truth when He said to the Samaritan woman that He will give living water that whoever drinks of it will never thirst again (John 4:14).
Those who study the world can see this. No matter what subject or which legacy others have left behind; those that are of God and from God, those are the ones that last throughout the ages. Everything that people have seek for themselves will sooner or later be forgotten or become irrelevant. The world cannot tell you what is your purpose because it didn't make you. Only your Maker in heaven can truly tell you what you are meant to do.
But God doesn't always reveal some unique or specific plan for our lives. Not everyone will know what is God's specific will for them. Actually, it doesn't really matter. God has told through the bible of what we are to do. In Matthew 28:19, Jesus's last commandment was for us to "Go therefore and make disciples of all the nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit," Jesus also said in Matthew 7:21-23 that not all those who have called Him Lord will go to heaven because they did not have a relationship with God. Throughout the bible, God has said obedience is better than sacrifice. Jesus also said those who love Him/God are those who obey His commands.
This means that as true Christians, we are to form a relationship with God. To form and keep that relationship, we need to live for Him, obeying His word. It's painful and difficult but if we truly want to know Him, it is necessary. As we live for Him, we will want to obey His commands which include encouraging and leading others to be closer to Him. We need to ensure we do this for the right intentions because the wrong ones will lead to burnout and a Christ-less eternity. When our art reflects the right heart, God is there to help us through it and we will draw closer to Him.