Various traditions have different answers on this. There's no consensus. (That may be your answer. The rest may be irrelevant.) --- Greg Bala has already addressed the Catholic view. Here are some Protestant ones, ranging from extreme Pentecostal to conservative Christian. None of these are universal. Some groups believe some of them, others think that some of the beliefs are insane, pure guff, or just wrong. I'm not saying which is which, just listing them out. - [Ability to pick up deadly serpents, not get bitten, and be immune to their poison if they do bit you][1] - Being overtaken with [Holy Laughter][2] - Prophecy - [Growling, dancing, shaking, barking like dogs, and even some even being stuck in positions of paralysis.][3] - Speaking in tongues On the less Charismatic end of the spectrum... - Possessing the fruits of the Spirit - a combination of Matthew 7:16 and Galatians 5:16-25. [Many non-Charismatic protestants see these fruits as evidences that we are filled with the Spirit.][4] > **Matthew 7:16 (KJV)** Ye shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles? > > **Galatians 5:16-25 (KJV)** 16This I say then, Walk in the Spirit, and ye shall not fulfil the lust of the flesh. 17For the flesh lusteth > against the Spirit, and the Spirit against the flesh: and these are > contrary the one to the other: so that ye cannot do the things that ye > would. 18But if ye be led of the Spirit, ye are not under the law. > 19Now the works of the flesh are manifest, which are these; Adultery, > fornication, uncleanness, lasciviousness, 20Idolatry, witchcraft, > hatred, variance, emulations, wrath, strife, seditions, heresies, > 21Envyings, murders, drunkenness, revellings, and such like: of the > which I tell you before, as I have also told you in time past, that > they which do such things shall not inherit the kingdom of God. 22But > the fruit of the Spirit is love, joy, peace, longsuffering, > gentleness, goodness, faith, 23Meekness, temperance: against such > there is no law. 24And they that are Christ's have crucified the flesh > with the affections and lusts. > > 25If we live in the Spirit, let us also walk in the Spirit. 26Let us > not be desirous of vain glory, provoking one another, envying one > another. [1]: http://global.christianpost.com/news/snake-handling-christians-faith-prophecy-and-obedience-75985/ [2]: http://www.bing.com/search?q=holy%20laughter&pc=MOZI&form=MOZSBR [3]: http://www.gotquestions.org/Toronto-blessing.html [4]: http://www.desiringgod.org/resource-library/sermons/be-filled-with-the-spirit