We have to pray within the will of God. If we could just pray people into salvation, we certainly would. But there’s this pesky thing called free will that we have to deal with. BTW – The best reason I can come up with for free will is that it must be kind of like how kids feel about their parents’ love. You’ll hear them say, “you have to love me, your my mom.” And because parents “have to love” their kids, it doesn’t count some how. So I guess if we had to love God, then maybe it wouldn’t count in a similar kind of way.
What ever the actual reason is, it’s clear that God has given us free will. We can’t pray people into salvation. We have to allow for free will. But that’s it. That’s the only place we have to stop. I believe we can pray people right up to the edge of free will. We can pray that they will get all their questions answered. We can pray that they will understand the message. We can even pray that they will know that’s it true. We can pray that God will work in their life such that the only thing left for the person to do is say, “yes.”