Romans 8:16 The Spirit itself beareth witness with our spirit, that we are the children of God: KJV
AQUAINT YOURSELF WITH THE WORKINGS OF INWARD WITNESS
Anytime I teach on the leading of the Spirit, I always try my best to explain what inward witness is using the traffic light colors. On the highway, when the traffic light signals "green", we know that's an unspoken command to go. All motorists will move without fear of being apprehended by traffic enforcement officers. When the traffic light signals "red", we know it means stop. If anyone moves, the danger it portends could be fatal because there's likelihood of collision with oncoming vehicles. The amber colour signals "get ready". The traffic light leads drivers without words yet drivers regard it as a valid means of traffic control and direction. That's how the inward witness of the Spirit works.
One primary way by which God leads all His children is through the inward witness. Whether we recognize it or not, that's another issue entirely. That 'knowing' we have from within us about an issue is known as inward witness. It is not a voice but a knowing within. Has it ever happened to you that you know something about a situation supernaturally without hearing a voice or seeing visions? I've been there severally. When you are about taking a step, that sense of inner peace and tranquility that gives you a "go ahead" from within is inward witness of the Spirit saying "go ahead" but that turbulence and lack of peace within that you can't explain even when all things seem right in the physical is inward witness saying "stop". Now, there's no believer that hasn't experienced this at one time or the other. Some would say, "when I wanted to board the bus, 'something' pulled me back". That 'something' is the inward witness of the Spirit at work.
Confusion persists because most believers are not acquainted with the workings of the inward witness of the Spirit. They have experienced it but they haven't come to terms with the fact that it is the way by which God will lead them primarily on almost all issues. They're expecting a "supernatural" leading like open vision and trance, whereas, God is leading them through inward witness almost on daily basis. I've been there severally but now I know better. There were days I wished a supernatural hand writes on the wall for me to read or an audible voice speaks to me in clear terms. Several times, I've desired to see Jesus appear to give me a word of direction. It is not in God's nature to always lead us spectacularly. If you can train your spirit man with the word of God and spend time in the place of prayer (especially praying in tongues), you'll recognize the leading of the Spirit through inward witness.
Spend 30 minutes daily praying in tongues. It will sharpen your sensitivity and enhance your ability to recognize the workings of the inward witness.