Evangelism Prayer and Fasting

You should continue to be led by The Spirit of God in evangelism prayer and fasting but if you are new to this, you could study, meditate and then in the fullness of time begin to consider and pray about the following matters.
Fasting?
Fasting before you evangelise is not compulsory, but if you are led to do so, here is another reason why you might want to do so.
Adam and Eve had everything they needed in the Garden of Paradise. But they ate of the forbidden fruit out of disobedience, seduced by Satan. They were cast out of Paradise and driven into the wilderness. Jesus freely entered the wilderness in order to regain Paradise for those who lost it. Jesus refused food to show his dependence on the bread of heaven, which is the word of God, that would sustain him not only in his physical hunger, but also in his hour of temptation as well.
Unlike Adam and Eve, Jesus exercised all the fruits of the Spirit. See Galatians 5:22-23 (NKJV):” 22 But the fruit of the Spirit is love, joy, peace, longsuffering, kindness, goodness, faithfulness, 23 gentleness, self-control. Against such there is no law.”
If you can be tempted and lack control over self, how can you exercise authority over lawless demons. You are still operating under their domain. During a time of testing we must be found faithful to the word and the will of God. Then we look and sound like our Saviour to the unclean spirits.
Evangelism Prayer and Fasting
In summary, where evangelism prayer and fasting is concerned, there are other types of fasting but let us spend some time here
dealing with our pride and repenting of our disobedience in the past, and let us stay in the word and in His presence
until we have established a humility that says:
my agenda no longer means anything to me and my meat is to do the will of the Father and to finish His work; receiving by faith, every other necessary grace to do so. Luke 4:13-14