The Spirit And The Trinity

Nobis autem Deus revelavit per Spiritum suum. Spiritus enim omnia scrutatur, etiam altitudines Dei. Quis enim hominum novit quae in homine sunt, nisi spiritus hominis qui in ipso est? Sic et quae in Deo nemo novit, nisi Spiritus Dei.. Rogo suppliciter, locum istum, ut pote illuminati a Deo arbitri, judicate; et utrum aequalis sit Patri vel Filio Spiritus sanctus, ex ipsa scientiae suae profunditate perpendite. Nemo novit Filium, nisi Pater, neque Patrem quis novit nisi Filius. Sed quia nec Pater, nec Filius, sine Spiritu aliquid novit, ideo quae in Deo sunt nemo scit, nisi Spiritus Dei; quia nec Spiritus scire aliquid sine Patre vel Filio potest. Quid est, nemo novit praeter Patrem, nemo praeter Filium, nemo praeter Spiritum sanctum, nisi quia in Trinitate praeter unitatem nihil possumus invenire? Legimus alio loco, Qui Filium non habet, nec Patrem habet. Itemque alio loco, Si quis Spiritum Christi non habet, hic non est ejus. Quod non potest non simul totum haberi, quomodo poterit dividi? Sancti Aviti Viennensis, ex libris contra Arianos Source: Migne PL 59.305c-d

God gives revelation to us through His Spirit. For the Spirit scrutanises everything, even the depths of God. What man knows what is in a man, unless the spirit of man which is in him? So what is in God no one knows but the Spirit. 1 I entreat here, as it is possible, that you judge illuminated by the will of God, even whether the Holy Spirit is equal to the Father or the Son, considering the depths of its knowledge. No one knows the Son but the Father, nor the Father but the Son. 2 But because neither the Father nor the Son know without the Spirit, therefore what is in God no one knows unless with the Spirit of God, because neither does the Spirit know without the Father or the Son. And why is it that no one knows beside the Father, no one beside the Son, no one beside the Holy Spirit, unless only in the Trinity in unity we find them? We read in another place: 'He who does not have the Son, does not have the Father.' 3 And again elsewhere: 'If a man does not have the spirit of Christ, he is not His.' 4 And if it is not possible but to have them all at the same time, how would it be possible to divide them? Saint Avitus of Vienne, from a work against the Arians 1 1 Cor 2.10-11 2 Mt 11.27 3 1 Jn 2.23 4 Rom 8.9