The greatest commandment is to love God and love others. Lev.19:18 “Love your neighbor as yourself.”

Jesus combined these 2 laws in Matt.22:36-40
 
The same Lord who gave the 10 Commandments to Moses came down to earth at Christmas, died on the cross to satisfy the requirement of that law, and rose again on Easter.
 
God is the source of love. We sing “Oh, how I love Jesus (why?) because He first loved me”.

People who love God will love others. The ability to love flows from God.  1 John 4:7-21
 
Because God first loved us, we love God.  Then we are able to love others.

We are saved by grace (God loved us), through faith (we love God), unto works (we love others). Eph.2:8-10
 
We are assured that our faith is genuine, if our love results in loving actions toward others.

Love is the evidence that Christ is in us. They will know we are Christians by our love.