A life apart from God is no life at all. Think about it. There are many things that can give us satisfaction. No matter what it is though, it will diminish at some point. That is why so many people get caught up in chasing more and more material things. The more they get the more they want. And this just leaves people with a void inside. Using something outside of its intended purpose usually ends up in failure.
A life in the Spirit is the fullest life possible. In the Holy Spirit we have leadership and direction in life. Christians have One who will teach them what the Scriptures mean. We have a Friend who has promised to never leave us. It is easy to become a Christian, but being a true disciple requires labor. The product is worth the work, though. A life dedicated to Christ will always yield peace, real love, and true satisfaction.