Service and Sacrifice

I came about something very interesting in the book Eternity Unveiled by Dr. Albert Odulele. He drew my attention to the fact that Sacrifice is not equal to Service in the eyes God. God delights in my service more than in my sacrifices.

He made me for service, not for sacrifice. My sacrifice can only be accepted when my service to him is genuine. I can be willing to sacrifice all I have (especially when I believe and have the hope I can reproduce them) but not necessarily willing to serve him...

Can this be true?

Thinking about this two scenario...
1. Willing to sacrifice all I have worked for but reluctant to spend time witnessing for God.
2. Willing to sacrifice as much time I can to witness for God.

Which of these scenario best describe me? Why was Pharoah more comfortable with releasing the Israelites to Sacrifice to God rather than to go and Serve Him? Exo. 7:16, Exo. 8:1 and Exo. 8:8.

I think the differentiator here is PRIORITY. Sacrifice is a form of Service, and it has value only when it's done out of Service. The priority should be on Service not Sacrifice. It is Service that gives sacrifice value before God.

Sacrifices done in Service to God always attract God.