There is power in God's presence. OT believers understood this. And because there is power in God's presence, God uses His presence to give us His grace. Understanding this helps unfold the mysteries of why God didn't bring the Gospel to the whole world until after the cross. Believers, being Temples of the Holy Spirit, bring that presence of God with them when they evangelize. That could not happen before the cross because no believer was indwelt with the Holy Spirit. Let that sink in. That same power of God's presence that we see all throughout the OT, The Tabernacle, the Ark of the covenant, the Temple, in Jesus incarnate, even raising Him from the dead and sitting Him at the right hand of the Father, glorifying Him, is with every believers when they evangelize to the dead, and lost. That, in and of itself is sufficient grace to enable a person to believe the Gospel, the Word of God, which also carries with it power. In the beginning was the Word, and the Word became flesh, and dwelt among us.
"Then Jesus said to them, "A little while longer the light is with you. Walk while you have the light, lest darkness overtake you; he who walks in darkness does not know where he is going. While you have the light, believe in the light, that you may become sons of light." These things Jesus spoke, and departed, and was hidden from them." John 10:35-36
"As long as I am in the world, I am the light of the world." John 9:5
"Then Jesus spoke to them again, saying, "I am the light of the world. He who follows Me shall not walk in darkness, but have the light of life." John 8:12
"You are the light of the world. A city that is set on a hill cannot be hidden. Nor do they light a lamp and put it under a basket, but on a lampstand, and it gives light to all who are in the house. Let your light so shine before men, that they may see your good works and glorify your Father in heaven". Matt 5:14-16
Bible verses about Jesus Being The Light Of The World
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Acts 1:4-8 "And being assembled together with them, He [Jesus] commanded them not to depart from Jerusalem, but to wait for the Promise of the Father, "which," He said, "you have heard from Me; for John truly baptized with water, but you shall be baptized with the Holy Spirit not many days from now." Therefore, when they had come together, they asked Him, saying, "Lord, will You at this time restore the kingdom to Israel?" And He said to them, "It is not for you to know times or seasons which the Father has put in His own authority. But you shall receive power when the Holy Spirit has come upon you; and you shall be witnesses to Me in Jerusalem, and in all Judea and Samaria, and to the end of the earth.""
Interesting that Jesus connects "Power" from the Holy Spirit with witnessing to the whole world. It's easy to assume that He's only speaking of the ability to preach, but He could quite possibly also be speaking of the power to allow one to respond.