“To love those whom we do not like means that we treat them as if we did like them — to choose to act kindly toward them even though we do not like them….The Bible does not ask us to like the brethren, it asks us to love them, and that means, therefore, something like this: we may not like certain Christians. I mean by that, there is none of this instinctive, elemental attraction; they are not the people whom we naturally like; yet what we are told is that to love them means that we treat them exactly as if we did like them. Now, the men and women of the world do not do that; if they do not like people, they treat them accordingly and have nothing to do with them. But Christian love means that we look beyond that. We see the Christian in them, the brother or sister, and we even go beyond what we do not like, and we help that person. Love your brethren — that is the exhortation with which we are concerned?
Martyn Lloyd-Jones on I John 3:16-18 in his book Children of God