And it shall come to pass, if ye shall hearken diligently unto my commandments which I command you this day, to love the LORD your God, and to serve him with all your heart and with all your soul. It is obvious that our serving God must flow out of our love for him. It is an overwhelming awe of His absolute love, power, holiness and glory. He that feareth is not made perfect in love. We love him, because he first loved us.
Perfect love drives out fear, for fear has to do with punishment.
If we have no certainty of salvation we must still fear punishment, and therefore cannot have perfect love. In fact, the word Islam means Peace and Submission to the will of God and Muslims are those who submit to God's will. But the Bible goes much further than this. It teaches that God wants an intimate relationship with us, his children, and while He created us for His glory, He also created us for friendship, love and intimacy. Indeed, God is selfsufficient, and does not need these things.