The one who believes (has faith) in God, obeys. And the one who loves God obeys. In her/his obedience s/he will love other believers. That love will be seen as fruit – the love itself and what it causes to happen – fruit that others (from believer to non-believers) can see. What they see in turn reflects God’s glory and leads to more people giving God glory.
In short, love is the Sine Qua Non of the Christian. But this is not the philos / eros love but the agape love. A love given that is merciful and graceful. For to be merciful is to withold what punishment is rightly deserved and to be graceful is to go beyond the crime and restore the sinner with more than s/he had before. This is not an easy love but a love given when we don’t deserve it. A love leading to us giving more than anyone merits.
We do not do this of our own emotional fortitude or intellectual prowess but through the forever Friend whom Christ has sent to counsel us – The Holy Spirit. The Holy Spirit is Truth in us and through us. He lives with us in the nitty gritty, teaching and leading, guiding and comforting and through us in both the beauty and beast that is life.