God has created mankind to Worship Him. Because of sin we are seperated from God and lost our relationship with our creator (Father), so our Heavenly Father decided to put His plan of redemption for mankind into action so he can find his way back into an intimate relationship with the Heavenly Father through the ulimate death of  Jesus Christ (His Son) on the cross. So, we are restore to the origional plan and that is to Worship God & God alone according to His Commandments.