Psalm 2:10-11

Now therefore, O kings, act wisely; be instructed and take warning, O leaders of the earth. Worship the Lord and serve Him with reverence (with awe-inspired fear and submissive wonder); rejoice (yet do so) with trembling. 

We can serve many things that bring us little benefit, but God is the only one who can break down all the barriers. It takes focus, time, and dedication, discipline and love for God to maintain a relationship with Him. The rewards of a relationship with God bring more to us than we to Him. God loves us more than we can comprehend.