Be patient, bearing with one another in love. Let's look at some of the words in this command. It indicates zealous effort. But our zeal needs to to be focused on guarding unity. Love does not delight in evil but rejoices with the truth.
Love always protects, always trusts, always hopes, always perseveres.
This doesn't mean that preserving unity is at all easy. We need to be faithful to the truth, to guard the teachings delivered to us to pass on to the next generation. We need to contend for the faith once delivered to the saints. But we must keep the unity of the Spirit, and we must do it in love. It is a command.