1 John 3:23-24 (KJV)
23 And this is his commandment, That we should believe on the name of his Son Jesus Christ, and love one another, as he gave us commandment.
24 And he that keepeth his commandments dwelleth in him, and he in him. And hereby we know that he abideth in us, by the Spirit which he hath given us.
These two verses summarise it all.
We believe in the gospel and as a result our faith and love for GOD results in that we love each other not in word but in deed. His commandment is to love and that demonstration of love through faith in Jesus Christ is the evidence that we are in Christ and that Christ is in us by the Holy Spirit. It is not complicated, it is just that simple.
In 1 John 3:18 (KJV) My little children, let us not love in word, neither in tongue; but in deed and in truth. John explains the type of love that is an outcome of faith and obedience in Jesus, we are to demonstrate. It is a love of action that is comes form the heart and not pretence (it is rooted in truth and Jesus is the Truth).  In 1 Corinthians 13:1-13 in the KJV it renders loves as charity. 1 Corinthians 13:13 (KJV) And now abideth faith, hope, charity, these three; but the greatest of these is charity. Strong describes it as “love, that is affection or benevolence; specifically (plural) a love feast: – (feast of) charity ([-ably]), dear, love.“. It describes that the love GOD gives to us is out worked to benefit other without consideration to receiving benefit in return even if they are our enemies. Luke 6:35 (KJV) But love ye your enemies, and do good, and lend, hoping for nothing again; and your reward shall be great, and ye shall be the children of the Highest: for he is kind unto the unthankful and to the evil.
In short “Faith has legs” and the legs are active love.
Let us keep it simple and encourage each other to grow in our faith and love for one another and those around us.
John 13:35 (KJV) By this shall all men know that ye are my disciples, if ye have love one to another.