Through out the new testament we read instructions to offer our bodies as a living sacrifice (Rom 12:1), deny ourselves (Mat 16:24), lose our lives (Mark 8:35), and hate our life (John 12:25). It is clear that when God saves us and we begin to live Jesus' mission, our lives become the property of God (who gave us our life to begin with).
However, it is very easy to forget this here in America and especially in the suburbs. The call of comfort, safety, and convenience is quite strong and it is very counter cultural to not pursue those things. But since our lives are not our own, we must.
I was reminded of this the other day. My wife and I stumbled across a television show called "Teen Cribs". It is a spin off of another show called "Cribs" where the rich and famous walk around their mansions and show off all of their stuff.
The same thing happens in "Teen Cribs". These kids walk around a massive home filled with all the finest things and they show off their room, their basketball court, their Porsche (that they are too you to drive), their swimming pool, and their game rooms. All the while bragging about how great their home is. The only problem is nothing in the home nor the home itself is theirs.
All of these kids have wealthy parents who have purchased the home, filled the home with stuff, and pay to maintain the home. The home is not theirs.
We do the same thing with our lives. We live where we want to live, speak to who we want to speak to, and spend our money on what we want. However, your life is not your own. It is God's and he has saved you and called you to live as a missionary in this world.
This means every decision from where you live to who you hang out with needs to made with the mission in mind. Our mission is to make disciples of Jesus and lead them to maturity (Mat 28:19) and I encourage you to do this remembering that your life is not your own.
For further reading on this topic check out "Don't Waste Your Life" by John Piper.