1) Infant: 1 Corinthians 3:1-2 But I, brothers, could not address you as spiritual people, but as people of the flesh, as infants in Christ. I fed you with milk, not solid food, for you were not ready for it. And even now you are not yet ready. In this context, Paul is calling the Corinthians "infants" and explaining why they were "infants". There were all kinds of gifts in the Corinthian Church, but also all kinds of sin. Because they had the gifts being active, they thought that was enough! Paul addressed that and explained that the gifts only reveal God's character, not the Corinthians one. This is also true for us, it doesn't matter how many gifts we have, if we don't have Christ's character, it mans nothing! And the essence of Christ's character is love. Because God is love! 1 John 4:8 He who does not love does not know God, for God is love.
2) Mature: Hebrews 5:14 But solid food is for the mature, for those who have their powers of discernment trained by constant practice to distinguish good from evil. Ephesians 4:13 Until we all reach unity in the faith and in the knowledge of the Son of God and become mature, attaining to the whole measure of the fullness of Christ. In the beginning of my christian life (i recounted this in some posts), the Holy Spirit spoke to me (taught me) about a subject and after that i open my Bible exactly in the text containing that subject (read post "Personal Testimony: Fasting"). Here the teaching was practical, the Holy Spirit led me to "practice" fasting and then taught me about it (usually the theory comes before the practice). But, as i grew in faith, the teaching got more profound, as when i prophesied to people, i had to believe that the things i spoke would come to pass, even if things were going good with them, as if i was going crazy by saying those things. That's why most people (with few exceptions) didn't believe what i said, for them, there was no way it could happen, but it did.
3) Mature like a child: Matthew 18:3 And he said: “Truly I tell you, unless you change and become like little children, you will never enter the kingdom of heaven”. I have something to share that fits this "stage of faith": Once the Holy Spirit told me that we (I and my wife) would leave the church and go to another one. I believed it and spoke to the pastor. Problem was that the Holy Spirit didn't say where to go, so, when i spoke to the pastor he was shocked. As i was part of the worship team, he asked me to talk to my fellow worshipers. When i told 'em that we were leaving, not knowing where to go, some were very "unkind" (not to say rude) and refused to believe that the Holy Spirit spoke to me. But i was immovable in decision to obey. In our last Sunday at this church, the pastor again asked me about where we were going to, i told him that i didn't know, so he kindly gave me a list of the churches (american and hispanic ones) around our area (Lake County, Illinois). We left not knowing where to go. So i started praying even more about it and one day i was reading that booklet and found a church right by my town, in a township that i didn't even know that existed and the Holy Spirit told me to go to that church (a small hispanic church). Next Sunday, we went there, as i entered the sanctuary, the Holy Spirit spoke to me saying that we were to stay there for a little while. During the service, the pastor asked us to stand and introduce ourselves. We did and told 'em that we were originally from Brazil and were visiting 'em. Next Sunday, we came back. At the end of the service i asked the pastor to talk with him. We went to his office and before i said anything, he started speaking: "When you entered the sanctuary and i saw you, God told me you were the guy He was bring to lead the worship team, because we were praying for a while for a leader and God said He was going to bring a worship leader. You are God's answer to our prayers. Besides, when you said you were brazilians, God remembered a promise He made for us (family). He is going to send us to Brazil. God told me He didn't forget about it. But, let me tell you something, you are going to be here for a little while and God tells you to leave, just leave!" I started crying because from the beginning was very painful the decision to obey and leave the church where i was born again and go to an unknown church. That's a genuine Mature like a child kinda faith, when you decide to obey no matter what, to believe to impossible, to trust "God will make a way where there seems to be no way", as the song goes. This is what Jesus is talking about when He said to "become like a little children", to trust without hesitation.
How to receive what we ask for? Matthew 21:22 And whatever you ask in prayer, you will receive, if you have faith. 1 John 5:14-15 This is the confidence (assurance) we have in approaching God: that if we ask anything according to his will, he hears us. And if we know that he hears us - whatever we ask - we know that we have what we asked of him. That's the key, asking according to God's will. Then you ask: "How can i know His will?" By knowing God! The more we know Him, the more He reveals His will for us. On the post that i showed above, there are specific things that God revealed about His will to my life.
How to receive without asking?: Psalm 37:4-5 Delight yourself in the Lord, and he will give you the desires of your heart. Commit your way to the Lord; trust in him, and he will act. The best example i have is my son (read post "Personal Testimony: My Son"). I always desired to have a son but never wanted to get married, of course, that was not God's plan. First, He gave me a wife and then, even if my wife couldn't get pregnant, He (God) intervened and gave us a son. If you delight yourself in the Lord, He will give you the desires of your heart that are in accord with His will.
Some examples of Faith in the Bible: Abraham (Genesis 12), Abel (Hebrews 11:4, Genesis 4).