1 John 5:21 says, Dear children, keep yourselves from idols. The Amplified Bible elaborates on this: Little children, keep yourselves from idols (false gods)--[from anything and everything that would occupy the place in your heart due to God, from any sort of substitute for Him that would take first place in your life]. (AMP)
It is imperative that you prevent any sort of substitute from becoming first place in your life. Fill your life with the true, living God, not a phony substitute.
You can tell what is important to you simply by examining how you spend your time. If you are spending so much time trying to make money that you don't spend any quality time with God, then wealth is more important to you than God. Likewise, if you are always spending time with friends and don't have any time to spend with God, then your social life is more important to you than God.
How you use your time is so important, because you can either invest it or waste it. However, if you waste your time, you'll never get it back. On the other hand, if you invest your time into forming a deep, close, personal relationship with God, then you will reap the rewards of such an investment for the rest of eternity.
Decide to put God first in your life: spend significant, quality, personal time with Him. Put the first, most important thing (God) first place in your life.