I believe that one can sense when they are lacking spiritually. I have mistakenly called it spiritually dead, its more of spiritually starved. This is something I've been experiencing lately, now that I am unable to attend church on Wednesday nights due to work. I have still gone on most Sundays but it just isn't the same. (Not to mention other factors that have distanced me from both the church and in some ways, God as well.) This was the first time I had been to church on a Wednesday since the fourth of July. The excitement I felt all day about going was matched only by the feeling I had afterwards of being full. It was similar to how you feel after a good meal. Not stuffed, as though you could burst, but full and satisfied.
I also had some revelations. I'm not throwing scripture out just yet, this is raw and I'll most likely touch on these in some later writings. First is that, we are truly, truly supposed to focus on pleasing God and looking after His attention and giving Him ours. Not concerning ourselves with how others see us or how they feel about us. That doesn't matter, and shouldn't matter to us. The only thing that matters is what God will say of us. Hopefully it is "Well done, my good and faithful servant."
The second thing is that you can't rely on people. People will fail you and disappoint you more times in your life than you will ever be able to count. And as humans, it seems in our nature to want to rely on each other, to depend on people for something. We want to trust each other. But this just leads to broken trust and broken hearts. God is the only one who will never let us down, and is always there no matter what. He is who we should turn to when things go wrong, when things are going right, and when things are just moving along. We shouldn't call up some person and demand they fix things or give us the answers or ask that they do the praying for us. We should step up to the plate, look to Heaven and have that relationship with God ourselves.
The last thing is, we cannot distance ourselves from THE church or God. Or both! You wither up spiritually and you begin to feel fatigued. It affects your every day and every aspect of who you are, especially when you have dived so far into His Word and His promises and doing His work and ministering. You will feel a not only a spiritual difference, but also a physical and an emotional difference.