Prayer changes things and it changes you.
God is sovereign and prayer can change things. This doesn't mean that we can twist God's hand to work the way we want. But God has decreed that certain things come to pass, only through our prayers. God loves to work through us and give us a reward for just co-operating with Him.
Certain course of events in our lives and the lives of those whom we pray for, can be changed by our prayers.
Prayer expresses your humility before God. Through seeking God's help in Prayer, you acknowledge that He has got control of everything. Because God is in control, we don't have to stress about things that are not in our control.
If you keep conversing with God often, you will see that you find easy to keep the devil at bay.
Intentional, frequent conversations with God will elevate the desire to spend more time with God. It would no longer be a chore, but pleasure.