The Torah indicates that the way to demonstrate our love for God is to obey "His" commandments. (Exodus 20:6 and Deuteronomy 5:10) However, when we read through the New Testament, it becomes apparent to us that something more is implied by those Scriptures. After all, the religious elite (Scribes, Priests, Pharisees and Sadducees) were careful to obey the commandments, but Christ said that they didn't truly love God. (John 5:42)
When Jesus was asked what was the greatest commandment contained in the Law, he answered by quoting Deuteronomy 6:5. He said: "Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind, and with all thy strength: this is the first commandment." (Mark 12:30) This commandment tells us how to love the Lord - with complete sincerity, conviction and intensity of effort.
It is also interesting to note in this regard, that Christ said that the second greatest commandment was to love your neighbor as much as you love yourself. (Mark 12:31) In the Gospel of John, we read that Jesus greatly elaborated on this theme. He said: "If ye keep my commandments, ye shall abide in my love; even as I have kept my Father's commandments, and abide in his love." (John 15:10) He went on to say, "This is my commandment, that ye love one another, as I have loved you." (verse 12) Jesus also said, "He that hateth me hateth my Father also." (John 15:23) Hence, one way to demonstrate our love for God is to love Christ and obey his commandment to love each other.
This is consistent with what John later wrote in one of his epistles. He said: "If a man say, 'I love God,' and hateth his brother, he is a liar: for he that loveth not his brother whom he hath seen, how can he love God whom he hath not seen? And this commandment have we from him, That he who loveth God love his brother also." (I John 4:20-21) Thus it is clear that in God's mind the two principles are inextricably linked.
In this connection, it is interesting to note an interchange between Jesus and Peter shortly before Christ's ascension to heaven. Jesus asked Peter three times if he loved him better than the other disciples loved him. (John 21:15-17) Remember too, that Peter had denied Christ three times just before he was crucified. (Matthew 26:69-75) Anyway, Peter was clearly bewildered by Christ's persistence in asking him about his love, but Christ responded with "feed my lambs" or "feed my sheep." In this instance, we see the clear implication was that the surest way to demonstrate love for him was to take care of his saints!
Brethren, if we truly want to demonstrate our love for God, then the best way to do that is to start with the brother or sister standing next to you.