Genesis 29:20:And Jacob served seven years for Rachel; and they seemed unto him but a few days, for the love he had to her.
Dearly beloved, you cannot separate love from service. Intense labour of 7 solid years felt like a few days to Jacob simply because he loved Rachel. Service to God be joyful if you truly love the Lord. If your service to God is getting burdensome, you begin to feel you are doing much for the Lord, then please you need to do a thorough examination of your love for God. Love has a compelling force that makes you serve the Lord with all your heart.
Deuteronomy 10:12:12 And now, Israel, what doth the Lord thy God require of thee, but to fear the Lord thy God, to walk in all his ways, and to love him, and to serve the Lord thy God with all thy heart and with all thy soul,
May the Lord help us to satisfy to the Second Demand of Love!