The Rechabites were told by their patriarch Jonadab to dwell "in tents" (Jeremiah 35:10). However, all of the strictures and paces they were put through having chosen not to partake of all of conveniences of (then) modern-life guaranteed their right-standing before God. At least one person it says:
"And Jeremiah said unto the house of the Rechabites, Thus saith the Lord of hosts, the God of Israel; Because ye have obeyed the commandment of Jonadab your father, and kept all his precepts, and done according unto all that he hath commanded you: Therefore thus saith the Lord of hosts, the God of Israel; Jonadab the son of Rechab shall not want a man to stand before me for ever." (Jeremiah 35:18-19, emphasis mine) In other words, God, speaking through Jeremiah, guaranteed that there'd be always be someone from that tribe whose heart was before Him.
So in order to become "intense", does that mean you have to dwell "in tents"? I don't think so. But the Indo-European root of both is the same.
Boiling Down
A thing's essence is what you're looking for. Because from there, provided you have the vision to see it through to completion, every step after will be not only in the right direction, but just as purposeful as the seed, from which it all came.
"And Nathan said to the king (David), Go, do all that is in thine heart; for the Lord is with thee." (2 Samuel 7:3)
I find that intensity simply is. It can swing both ways. Either into an all-consuming compassion whose impetus is the bright and white-hot love that God gives you (Mother Teresa points to God having smiled at her as the driving force of her ministry to the poorest of the poor). Or, into a vehement rage that is nothing if not detrimental and destructive. There are a-thousand variables in between and innumerable shades of gray—even within the individual. But the intensity's the thing. It's there, like a singularity, waiting to explode and take on a life of its own. How will you direct it?
"Take my yoke upon you, and learn of me; for I am meek and lowly in heart: and ye shall find rest unto your souls." (Matthew 11:29)
Jesus. "Meek" and "lowly in heart". The same Jesus who fashioned his own instrument of scourging in order to drive the tax-collectors and ware-sellers from their kiosks within the temple (John 2:15) is the same Jesus who was Himself scourged before He was nailed to the cross.
"And they shall mock Him, and scourge Him, and shall kill Him: and the third day He shall rise again." (Mark 10:34)
Look at a sword. Something that, to this day, with all the advancement in battlefield technology, still symbolizes war. It has a double-edge. And even then, you can still choose to pick it up—or not. The same Jesus who told His disciples to "take nothing for their journey" (Mark 6:8) later—after reminding them of those words—told them to go well equipped (Luke 22:36-38): "And they said, Lord, behold, here are two swords. And He said unto them, It is enough." Two swords? That's intense.
"Then said Jesus unto Peter, Put up thy sword into the sheath..." (John 18:11)
We are all like great mixtures of various ingredients. God is stirring us around and around in circles and we are slowly congealing, coalescing into that which He'd have us be. Into that which He wanted us to be when He first thought of us (heart? mind?). And remember, God "has His way in the whirlwind." (Nahum 1:3) Speaking of the heart, surely you've heard of arteriosclerosis? Don't worry. It's a disease where the artery walls develop plaque to where blood flow is constricted. It's not good, certainly not. Obversely, when a person's blood pressure's too high, under certain circumstances, the heart will actually pump with a force that causes the arteries to expand, ultimately causing the heart to weaken and fail. And that's not good either. So pace yourself. Don't let your intensity get the best of you. It's there for a reason and for a season.
Boiling Over
..."for the things concerning me have an end." (Luke 22:37) Jesus came for a reason. For thirty-three short years He showed us how to live in and among all of the various influences vying for our attention and intensity. Don't be ashamed of who you are. And don't be afraid to "assert yourself in a confident manner", to quote Calvin—if the time and place call for it: "Be ye angry, and sin not:" (Ephesians 4:26) Keep stirring and allow God to pour you out. That's what we're here for. To bless. To help and heal. To anger and enrage and...calm. To affect:
"But it is a good thing to be zealously affected always in a good thing, and not only when I am present with you." (Galatians 4:18)
"And it came to pass, when the king sat in his house, and the Lord had given him rest round about from all his enemies; That the king said unto Nathan the prophet, See now, I dwell in an house of cedar, but the ark of God dwelleth in curtains." (2 Samuel 7:1-2) In tents.