Matthew 22: 36-39 New International Version (NIV)
36 “Teacher, which is the greatest commandment in the Law?”

37 Jesus replied: “‘Love the Lord your God with all your heart and with all your soul and with all your mind. 38 This is the first and greatest commandment. 39 And the second is like it: ‘Love your neighbor as yourself.’ 

John 3:16 New International Version (NIV)
16 For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.