"For our gospel came not unto you in word only, but also in power, and in the Holy Ghost, and in much assurance." 1 Thessalonians 1:5
"If any man be in Christ, he is a new creature." 2 Corinthians 5:17
"I know thy works, that thou hast a name that thou livest, and art dead." Revelation 3:1
To one who is a student merely, these verses might be interesting, but to a serious man intent upon gaining eternal life they might well prove more than a little disturbing. For they evidently teach that the message of the gospel may be received in either of two ways: in word only, without power, or in word with power. Yet it is the same message whether it comes in word or in power. And these verses teach also that when the message is received in power it effects a change so radical as to be called a new creation. But the message may be received without power, and apparently some have so received it, for they have a name to live and are dead. All this is present in these texts.--A.W. Tozer, God's Pursuit of Man
I tremble to think how often my witnessing has been in "word only." How often have I gone out in my own strength, with only a token prayer. "God, please be with me today and help me as I communicate your Word." This prayer neither touched my heart nor sprang from faith, but was the kind of thing that I did to tick off a mental checkbox: "I'm supposed to pray--done."
Saints of old spoke of wrestling in prayer. Who are you wrestling against? "For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places." (Ephesians 6:12)
In order to come up against that stronghold, that heavily guarded castle, that bound person, we NEED to come in the power of God. There is no other hope. There is no other way. And in order to see walls come crashing down, chains burst asunder, and opposition flee, we must gain the victory in prayer long before we actually encounter the person face to face with the message of the gospel.
So I have started laboring in prayer for certain individuals, spending time, praying out loud, praying fervently, beseeching God to gain the victory, asking in faith, and not giving up until God has given me the assurance that the victory is won.
I think that's going to go better than my old approach.