Charity is the pure love of Christ (see Moroni 7:47). This love of Christ is two-directional by nature. The pure love Christ has for the children of men is charity, and the love which they have for the Savior, that comes with faith and repentance, is also charity.
When we are filled with charity we are filled with the perfect love of the Savior for us. “We love him, because he first loved us,” testified John (1 John 4:19). Such charity in our hearts is then manifested by our pure love of Christ, by our obedience (see John 14:15; 1 John 3:24), and by our love and charity for our fellowmen (see 1 John 3:16-18; 1 John 4:7-11).