What does Mark 11:24 mean?

Jesus has killed a non-fig-bearing fig tree as an illustration of the coming destruction of a religious system which has stopped bearing spiritual fruit for those who worship God. He and the disciples are standing on the Mount of Olives. They are looking at the Temple Mount, where for generations Jews have brought sacrifices for their sins, in order to be right with God so He can hear their prayers.

A short time before, a rich young man had asked Jesus how to inherit eternal life (Mark 10:17–22). The old way—the temple way—was to obey the Law, and to atone by sacrifices. With Jesus' crucifixion and resurrection, such ceremony is no longer needed. Belief, meaning humble trusting faith—the kind reflected in an attitude of forgiveness towards others (Mark 11:25)—is all we need to come before God. There is no longer a call for rituals performed in a sacred space with priests as middlemen (Hebrews 4:16). The disciples, however, aren't ready to abandon the temple and its trappings. They still see the grand cultural symbol, not the corruption underneath (Mark 13:1–2).

Jesus is not endorsing the modern Word of Faith movement. Nor is He suggesting that God operates as a cosmic vending machine, doling out wishes. Believing that God will answer our prayer is not a spell that we place on God so He must give us what we want. The context of the promise of prayer is God's ordained ministry, if we ask with the right intentions (James 4:1–3) and within God's will (1 John 5:14–15). The Bible promises "if any of you lacks wisdom, let him ask God, who gives generously to all without reproach, and it will be given him" (James 1:5). If we pray for wisdom first, and ask in God's will, we will receive what we ask for. If we ask without wisdom, we won't ask according to His will, and have no reason to expect such a request to be granted.