"By this shall men know that you are my disciples...." The telltale sign of the Christian is his love. What the world needs is more Christian love according to the philosopher Bertrand Russell who was an atheist. Jesus mentioning the agape love of the brethren that the world will see as a witness to the genuine believer. NB: It doesn't say we shall be known by our success, possessions, education, culture, talents, etc., but by our love alone. Prosperity theology seems to think that we need to cash in our spiritual lottery ticket and just name it and claim it on our way to our dreams. I recall the spiritual song, "Once you've experienced it, you want to pass it on [the love of God]."
We want to make converts to Christ, not to our opinions. It doesn't say that we want to pass on our school of theology or favorite doctrines and make converts to our private way of thinking, but to reach out it sacrificial love to the world in the name of Christ as his ambassadors.
He that loves knows God, for God is love according to 1 John. If we do not know love, then we do not know God; for God is love. There is nothing wrong with a person that has learned to love with the love of Christ in his life, even if he doesn't have a firm grasp on doctrine; as long as his heart is in the right place, that is of paramount importance. Right belief (orthodoxy) is vital, but not at the expense of right conduct or behavior (orthopraxy). The faith we have is the faith we show, not the faith we talk about. 1 John 3:17 says that if we say we love God and behold our brother in need and have no compassion, we cannot say that the love of God dwells in us. The Christian should see needs and not have to be shown or made to see them. It is an honor to be able to come to the aid of a fellow believer in his time of need.
When we say that God is love, we are not saying that love is God. Love is the only attribute that shows God's personal relationship with us and that God is a personal God. It must be expressed and manifested; God did demonstrate it sacrificially by sending his Son. God defines love and the more we apprehend love the more we understand God's nature.
God is light and God is Spirit according to Scripture also, but these do not relate personally to us. Everything God does is defined in love, God doesn't know how to be unloving, but it doesn't just say God loves, but God is love--the personification of his nature. It is not so much an attribute as what God really is if we care to know him. God's love is unconditional and infinite (to know the love of Christ!). God's love cannot be measured nor compared and God had to send His Son to demonstrate it. Soli Deo Gloria!