Apart from Him, they cannot love. Unless we are first loved by Jesus, unless we are first joined to His death and His life by faith, unless we are buried with Him by Baptism and are raised with Him and seated with Him in glory, unless we are in communion with Him and He with us, we will not and cannot love one another. Faith and love always run together. We cannot speak of faith in Christ without love for one another. And we cannot speak of love for one another without faith in Christ.
Love is the fruit of faith, like apples on an apple tree or oranges on an orange tree.
If the tree is alive and well and drawing the nutrients from the soil and the energy from the sun, it produces fruit. If faith in Christ is alive and well, drawing on Him through the Word and the Sacrament, it produces love. God's love was shown in this, that He sent His only Son into the world, so that we might live through Him. We didn't love God. He loved us, and He sent His Son to be the atoning sacrifice for our sins.