Thank you for bringing this verse up Daughterforlight,
I was just looking at this verse the other day. It is one of the verses that is so critical to the doctrine of the Trinity as it has been understood for nearly two millennia. This verse proves that although the Lord Jesus Christ and the Spirit are two separate persons, they are in fact one being. They are always in agreement with and in communion with each other. They are one being, hence the name, Tri-Unity (or shortened, Trinity). Tri-une means three in one. God is three, yet at the same time one. This is a mystery to the human mind. These kind of ideas are usually not hard for children though.
2 Corinthians 3
1 Are we beginning to commend ourselves again? Or do we need, as some do, letters of recommendation to you, or from you? 2 You yourselves are our letter of recommendation, written on our hearts, to be known and read by all. 3 And you show that you are a letter from Christ delivered by us, written not with ink but with the Spirit of the living God, not on tablets of stone but on tablets of human hearts. 4 Such is the confidence that we have through Christ toward God. 5 Not that we are sufficient in ourselves to claim anything as coming from us, but our sufficiency is from God, 6 who has made us sufficient to be ministers of a new covenant, not of the letter but of the Spirit. For the letter kills, but the Spirit gives life. 7 Now if the ministry of death, carved in letters on stone, came with such glory that the Israelites could not gaze at Moses' face because of its glory, which was being brought to an end, 8 will not the ministry of the Spirit have even more glory? 9 For if there was glory in the ministry of condemnation, the ministry of righteousness must far exceed it in glory. 10 Indeed, in this case, what once had glory has come to have no glory at all, because of the glory that surpasses it. 11 For if what was being brought to an end came with glory, much more will what is permanent have glory. 12 Since we have such a hope, we are very bold, 13 not like Moses, who would put a veil over his face so that the Israelites might not gaze at the outcome of what was being brought to an end. 14 But their minds were hardened. For to this day, when they read the old covenant, that same veil remains unlifted, because only through Christ is it taken away. 15 Yes, to this day whenever Moses is read a veil lies over their hearts. 16 But when one turns to the Lord, the veil is removed. 17 Now the Lord is the Spirit, and where the Spirit of the Lord is, there is freedom. 18 And we all, with unveiled face, beholding the glory of the Lord, are being transformed into the same image from one degree of glory to another. For this comes from the Lord who is the Spirit.
Here's a good explanation, I think:
"The Lord is the Spirit," that is, Christ is the Holy Spirit; they are one and the same. Not one and the same person, but one and the same being, in the same sense in which our Lord says, "I and the Father are one." It is an identity of essence and of power. Christ is the Holy Spirit, because, being the same in substance, where Christ is, there the Spirit is, and where the Spirit is, there is Christ. Therefore this same apostle interchanges the three forms of expression as synonymous, "the Spirit of Christ," "Christ," and "the Spirit." Rom 8, 9, 10. The Holy Ghost is everywhere in the Bible recognized as the source of all life, truth, power, holiness, blessedness and glory. The apostle, however, had in the context spoken of Christ as the source of life, as delivering from the death and bondage of the law. He is and does this because he and the Spirit are one; and therefore wherever Christ is, or in other words still, wherever the Spirit of Christ is, or in other words still, wherever the Spirit is, there is liberty. By turning unto Christ we become partakers of the Holy Spirit, the living and life-giving, because he and the Spirit are one, and Christ dwells in his people, redeeming them from the law and making them the children of God, by his Spirit.
Charles Hodge, An Exposition of the Second Epistle to the Corinthians
As much as it would be convenient for those who dislike the doctrine of the Trinity, it really isn't associated with the RCC. It was around before they really came into full existence. Many people try to use the RCC as a straw man to fight against the truth behind the Trinity, but this is all futile. Anyone who has done a little research knows better than this.
There's always an ulterior motive behind a denial of the Trinity. I see it happen every time. Something strange always follows, or comes along with this.
Travis