What is it that gives capacity to the believer? Is it new birth, or is it the possession of the Holy Spirit? — Gateshead-On-Tyne.
YOUR question is a trifle difficult to answer inasmuch as the word capacity may mean somewhat different things to different minds.
It is very evident from 1 Corinthians 2:14, that man in his natural condition has no capacity at all to entertain the things of God. He cannot receive them.
In Romans 7 we find the struggles of a new-born soul. We can see that a capacity exists for recognizing and approving what is good, though the power to execute it is lacking. There does not appear to be as yet a capacity for understanding, though there are divinely-implanted instincts.
In 1 John 2:20-27, we read of the “unction” or “anointing,” —referring to the Spirit; by it we “know.” The same anointing “teacheth you of all things.” Capacity for the understanding of the things of God, the power by which we consciously possess them, is by the Spirit This is illustrated in the history of the disciples. Born again as they were, they had divinely-given instincts, and hence they recognized in Jesus the Christ of God and clung to Him. Yet they did not understand in any proper way the wonderful teaching that He gave them until He was gone and the Spirit was given. Again and again He had to comment on their lack of understanding, for “These things understood not His disciples at the first: but when Jesus was glorified, then remembered they that these things were written of Him” (John 12:16). Speaking of this the Lord said, “At that day ye shall know...” (John 14:20).
In short, therefore, we should answer the question you raise by saying that, while as a result of new birth we possess what we may call an instinctive capacity — a capacity of divinely given desires and feelings, our capacity for an intelligent reception of the things of God lies in our having received the Holy Spirit — and in our walking so as not to grieve Him.