Well...Yes. before you were a believer, you either went to church or someone witnessed to you, and you felt convicted and subsequently gave your life to the Lord, am I right. That's that Holy Spirit brother. Is the Holy Spirit only for believers? Well let me ask you this, did Jesus die for believers only? Does He only love believers?
God wants a bigger harvest and loves all and tries to draw everyone to Him. That's the job of the Holy Spirit. Have there ever been atheists converted to the Lord? Satanists? Witches? You bet there have been. You think they do this on their own? (haha!)
No Edward only the Born Again believers have in them the Holy Spirit Romans 8:9 But you are not in the flesh but in the Spirit, if indeed the Spirit of God dwells in you. Now if anyone does not have the Spirit of Christ, he is not His.
The conscience is a whole different ball game.
Ah, good question. Does the Holy Spirit dwell in non- believers? No I don't think so. Does He come to them at moments, to teach them, convict them, make them think? He sure does. It's an acquired conscience brought on by the Holy Spirit. Do infants know the difference between right and wrong? No. They will wander into the pool and drown, wander into traffic, get into all sorts of mischief. Oh so it is the parents that teach the infants right and wrong you may say? Really? What about the households where the parents are atheists or satanists, and the children get saved somehow? Is that the work of the parents also? I don't think so. Can unbelievers heal people? Can baby Christians? No. Why not? The Holy Spirit doesn't dwell in them. Mature Christians, who have a good foundation in belief allow the power and Love of God flow through them to affect healing and so forth. So everyone has the Holy Spirit, but Christians have more. It makes too much sense. God has had this plan since before He created man. He already knew that man left alone would reject God. So He says, I'll go poke them at times with my Spirit. Show them some light to guide them.
Can anyone, quench the Spirit so much that He leaves forever. Perhaps so. I think it takes a lot though because God is pure love and longsuffering.
Motherly instincts are not conscience. Animals do not have a conscience. They have no spirit, only soul and body. Animals were not created in Gods image, man was. Scripture says that multitudes will be saved out of the great tribulation. This wont be the work of believers, it will be the work of God (Holy Spirit) done through believers. All believers do, is to sow seeds and water seeds that have been planted. God gives the increase through His Holy Spirit.