Two quotes from Austin Farrer on the Holy Trinity:
From The End of Man p.70–71
"The heart of being, the blessed Trinity above all worlds, is not a mystery by which the knowledge of Godhead is withheld from our inquiring minds. It is a pattern of life into which we ourselves, by an unspeakable mercy, are taken up. For Christ joins us with himself in the continual , practical, daily choice of his Father as our father. Why, he makes us part of himself, he calls us his members, his eyes, and tongue, his hands and feet. He puts us where he is, in Sonship to his Father, and opens to us the inexhaustible and all–quickening fountain, the Spirit of Sonship, the river of life, the Holy Ghost."
From Saving Belief p.65–66
"The grand rule of theology is this: nothing can be denied of God which we see to be the highest and best in creaturely existence. Now in us, personal relationship is as valuable as personality itself. Friendship, mutual discourse, common action —these things are as valuable as the power to think and to feel; without them, we might scarcely care whether we could think and feel, or not. How can we deny mutual relation in the Godhead? God is love; not only loving to ants like us, but related by relations of love on his own level. The doctrine of the Trinity does not pretend to make God intelligible. It lays down certain requirements. It says that if God is to be God, the Godhead must be at once more perfectly one than any one of us, and allow also for a mutual love more outgoing than is found in any two of us. We do not know how these seemingly opposed requirements are fulfilled and reconciled in the Godhead; we only know they must be. If we wish, we may define the divine level of being as that level, above all our conceiving, where unity of life and discourse of mutual love most perfectly combine. I hope you will see that this is not an empty speculation, a pretence of knowing what cannot be known. God is whom we worship; we worship the sovereign unity, we worship the infinite love; nor do we worship two realities, we worship one God who is both."