It is right and salutary to recognize the riches of Christ and virtuous works in the lives of others who are bearing witness to Christ, sometimes even to the shedding of their blood. For God is always wonderful in his works and worthy of all praise. Nor should we forget that anything wrought by grace of the Holy Spirit in the hearts of our separated brethren can contribute to our own edification. Love builds communion between individuals and between Communities. If we love one another, we strive to deepen our communion and make it perfect.
Love is the great undercurrent which gives life and adds vigour to the movement towards unity.
This love finds its most complete expression in common prayer. When brothers and sisters who are not in perfect communion with one another come together to pray, the Second Vatican Council defines their prayer as the soul of the whole ecumenical movement.