There must be a wrestling not only against sin and temptation, but a wrestling even with God. Jacob in Genesis wrestled with a man all night, fighting for what? [Gen. 32:22-32] Fighting who? He fought for the blessing of a man? Though this 'man' wrestled with him all night, in a moment he was able to end the matter by merely touching Jacob's hip. What reason for all the struggle? Jacob had to want this blessing. When it was finished, this 'man' gave Jacob the name Israel, and Jacob had determined that he had wrestled with God. Who can change a man's name? The courts? The judges? Parents? Jesus did, and thats interesting now isn't it, for don't we all know Simon the son of John as Cephas which means Peter [John 1:42] We wrestle with God so as to be His people.
Job wrestled with God. Righteous without wrong doing, serving God faithfully, but His suffering had to come about so that He might show God as the source of his EVERYTHING. Suffering is not punishment, but rather it is sharing in Christ's affliction. Who knew more suffering than Jesus, and yet we find the disciples of Christ "rejoicing that they were counted worthy to suffer dishonor for the name" [Acts 5:41]
Here is my point. The people of God, Israel, are real, and they will really wrestle for their faith. They will wrestle with unbelief like David in Psalm 42-43. And who do we wrestle with in order that we may believe in God? We fight the self and seek the LORD. God's people may not be able to explain everything, but they will wrestle to be able to answer everyone who asks what the hope is that lives in their heart. God's people will wrestle, and they will be sanctified. Will they overcome on their own strength? Never, and thus we NEED Jesus, the free gift of God that brings eternal life [Rom. 6:23] For Israel, God's people, has never become God's people by their own efforts.
6"For you are a people holy to the LORD your God. The LORD your God has chosen you to be a people for his treasured possession, out of all the peoples who are on the face of the earth. 7It was not because you were more in number than any other people that the LORD set his love on you and chose you, for you were the fewest of all peoples, 8but it is because the LORD loves you and is keeping the oath that he swore to your fathers, that the LORD has brought you out with a mighty hand and redeemed you from the house of slavery, from the hand of Pharaoh king of Egypt. 9Know therefore that the LORD your God is God, the faithful God who keeps covenant and steadfast love with those who love him and keep his commandments, to a thousand generations, 10and repays to their face those who hate him, by destroying them. He will not be slack with one who hates him. He will repay him to his face. 11 You shall therefore be careful to do the commandment and the statutes and the rules that I command you today.[Deuteronomy 7:6-11]