Hmm...well, what is prayer? I’ll take the general idea that prayer is conversation with God. I try to start my prayers with praise and thanksgiving, followed by petitions, conclude with more thanksgiving and end with "thy will be done". I wouldn’t want or trust anyone else to run this universe.

So absolutely prayer is necessary, because praise and thanksgiving is the least that we can do in return for the graces we’ve received. God wants our petitions, because it means that we trust Him enough to turn to Him with our troubles, and respect Him enough to ask for stuff instead of just sitting back expecting stuff to happen.

I don’t want future generations to look back and say "Gee, why did Adam and Eve eat the forbidden fruit? God’s instructions were so clear." or "Why did she look back at Sodom and be turned into a pillar of salt? God’s instructions were so clear." or " Why did they steal at Jericho? God’s instructions were so clear." or similarly, "Why did the people not pray enough? It’s so simple. God’s instructions were so clear." I’m not sure, but I think the vision of Mary appeared to someone and she simply instructed "Pray more."

God hears all prayers. His ways are not our ways. We petition, then we trust in His divine providence. We do not know when or how our petitions are answered, but we know that God is all good, all the time. How long was it before the Israelites were delivered from Egypt? How long was it before the Messiah arrived? And was the Messiah in the form that the people expected? Look for His goodness in the world, more so than for specific results to our prayers. Look for Jesus and hold on fast to him; and trust that no matter what, God is in control, and that all is well in the bigger picture of things.

Peace of Christ be with you.