Did Sodom have the same chance as Capernaum which saw many signs and miracles? No. Did everyone at the time of Abraham in Ur have equal opportunity to respond to God's call, or did God single out him and call him in a special way as his chosen one? Evangelicals who believe in a chosen people (Israel) have a hard time admitting that God can choose individuals as well and that we are elect or chosen even before we are born. Did Esau have the same opportunity as Jacob whom God loved before he was born, while He hated Esau?
Revelation 3:20 is often quoted to say that God is standing at the door (i.e., of everyone's heart) and knocking for permission unto salvation. Let's look at the other verses in the letter to Laodicea while we quote this verse as it is often quoted out of context. Actually, Jesus says, "As many as I love I rebuke and chasten, be zealous therefore, and repent." Doesn't this mean Jesus discriminates? He is standing at the door of the church to read it in context and is addressed to the lukewarm believer who is out of fellowship--just being saved doesn't mean fellowship! Jesus has no fellowship with unbelievers either, so the "cold" person may not refer to an unbeliever, but to a believer distancing himself from Christ. Do Christ and Belial have anything in common that they should fellowship? The believer that offends Christ is the lukewarm, complacent one. Jesus said to one inquirer, "You are not far from the Kingdom of God." Psalm 119:155 says, "Salvation is far from the wicked...." If salvation is far then how can they have equal opportunity with those to whom it is near? [A paradox!]
The "whosoever" of John 3:16 is often cited out of context as evidence that anyone can get saved. Actually, Christ said that "No one can come to the Father unless it has been granted him of the Father" (John 6:65). And "the Father draws [the wooing of the Holy Spirit] him" in John 6:44. You see, if God does woo all people the same, then the only way to get saved is by being better than someone else (But Scripture says in 1 Cor. 4:7, "Who makes you to differ? What do you have that you didn't receive?" Jonah says, "Salvation is of the Lord." This means it is not a cooperative venture where we do our best and God helps us. It's all grace and God gets all the glory. Soli Deo Gloria. This implies no merit system.
Does anyone still not believe that the Holy Spirit doesn't take many times to sink in? The "whosoever" implies that anyone who believes will be saved but it doesn't say all can believe. "If anyone wills to do His will he shall know of the doctrine..." (John 7:17). Ultimately, our salvation is in God's hands and He chose us--we didn't choose him. ("I chose you and you didn't choose me..." as Jesus says in John 15:16.) (Cf. Eph. 1:5,11 [predestination] and Rom. 8:29-30.) Soli Deo Gloria!