“Until now you have asked for nothing in My name; ask and you will receive, so that your joy may be made full.” John 16:24
Jesus promised that “Truly, truly, I say to you, if you ask the Father for anything in My name, He will give it to you” (John 16:23). This condition for answered prayer and its resulting fullness of joy is not just a formula with which to end a prayer. “In My name” implies representing Him and what He stands for, so that our prayer could truly be His prayer as well.
For example, our prayer must be in His will. “...if we ask anything according to His will, He hears us...we know that we have the requests which we have asked from Him” (1 John 5:14-15).
We need also to recognize that God’s great purpose in creation is of higher priority than our own personal desires, so this should be of first order in our prayers. Jesus said: “When you pray, say: ‘Father, hallowed be Your name. Your kingdom come’” (Luke 11:2). We can also pray for our own needs, of course, especially for God to “lead us not into temptation” (Luke 11:4), the closing request in His model prayer.
It is good to seek God’s wisdom in all our decisions and undertakings, so that we can be confident we are indeed in His will, but our request for such guidance must be sincere and in willingness to act on His answer. “But if any of you lacks wisdom, let him ask of God...But he must ask in faith” (James 1:5-6). And it should be obvious that the requests be made with a clear conscience before God. “If I regard wickedness in my heart, the Lord will not hear” (Psalm 66:18).
But when we are indeed confident that we are praying “in His name” with all that this implies, then we should pray earnestly, for “The effective prayer of a righteous man can accomplish much” (James 5:16), and when the answer comes - as it will in God’s time - then our joy indeed will be full!