It is not possible to be a good person apart from God. When people argue that they don’t need to believe on God because they are already “good” people, my response is that this is impossible.
Anything apart from God is not good in of itself. Since we are only reflections of God, only when we unite our actions to God can we reflect goodness as coming from true Charity itself. This is why there is no greater love than he who lays his life down for a fellow man because what does he benefit for himself in dying? Acts of true goodness are rooted in total self-giving. Total self-giving is only possible from God Himself because this is unconditional love. Our very nature itself is only a mere reflection or image of God; we cannot be God Himself. You cannot change the nature of something simply by thinking it is something else. Therefore, mere reflections or images of good are not purely good unless they are united with Goodness itself, that is God. All actions that reflect good are tainted with selfish motivations one way or another, just like a reflection of a table cannot be the table itself, and the reflection is not a perfect image of the table because it is only a reflection. Perfect acts of goodness are only possible rooted in God.
Being a “good” person is not enough to be in union with the objective nature of our existence, that is union with Goodness, union with Charity, union with God. It is not enough to exist just “being a good person”. We most go deeper into Goodness, so that our works are authentic acts of Charity. When Charity is flowing through us, we become lights in the world that accurately reflect Goodness as it really is working in the Body of Christ. So when Jesus says when you served your fellow man, you served Me not because we simply did good works but because our works were united in Christ flowing only from God’s grace. Therefore , that is why it says “Every good and perfect thing is from above. “ (James 1:17) Notice it doesn’t say from within, or from ourselves. True Charity is divine and it is a gift that comes from grace. It is through us not from us that good works are done. Let Charity be your inspiration. Let Goodness in its purest form be your motivation. Seek beyond yourself because you really were meant to be a firework like Katy Perry said, just not from your own lighter.