“And if it seems evil to you to serve the Lord, choose for yourselves this day whom you will serve, whether the gods which your fathers served that were on the other side of the River, or the gods of the Amorites, in whose land you dwell. But as for me and my house, we will serve the Lord.” (Joshua 24:15, NKJV)
A sincere service of God can only come from a free and willing devotion of the heart. We should male a choice for God himself will not force us. We must serve him with all of our heart.