If you are not with God or you have drifted from Him then you are going to feel emptiness, it is inevitable.
The reason why we feel this emptiness is because there is a void within us only God can fill.
33 But seek ye first the kingdom of God, and his righteousness; and all these things shall be added unto you. Matthew 6:33 KJV
Our whole being needs the one who made it to satisfy our longing for divine connection which only God Himself can deliver, we also need God to sustain our existance on this earth where our mind, body, soul and spirit co-exist.
During this lifetime we will face trials and tribulations but having God’s presence in our lives during those challenges gives us comfort.
11 Why art thou cast down, O my soul? and why art thou disquieted within me? hope thou in God: for I shall yet praise him, who is the health of my countenance, and my God. Psalm 42:11 KJV
Earthly success is temporary but if we want substantial and worthy achievements in this lifetime it can only be gained through the serving of Christ Jesus, all things on earth will eventually pass away, but only God is everlasting and that is why serving Him is worthwhile because the results are everlasting and not just temporary.