Yes and no, sometimes God punishes us when we sin. Other times he does not. Our sins can be big and small, and sometimes sins require quick judgment. Other times they don't. We sin every day it God is not always punishing us for all our sins. He is patient and kind and lets us go through life as we, hopefully, seek to be more like Christ. We fail along the way, and God's patience endures (Romans 2:4).
The word "punish" has different meanings. The dictionary defines it as...
Punish: "to subject to pain, loss, confinement, death, etc., as a penalty for some offense, transgression, or fault: to punish a criminal. 2. to inflict a penalty for (an offense, fault, etc.): to punish theft. 3. to handle severely or roughly, as in a fight. 4. to put to painful exertion, as a horse in racing," (http://dictionary.reference.com/browse/punish?s=t).
The above definition is a "denotation" which is a direct, to-the-point explanation. However, words also have "connotation" which is the secondary meaning or the suggested meaning that often carries emotional weight. For example, a home is a place to live (denotation), but it is also a place of warmth and comfort (connotation). Punishment generally has a very negative connotation to it, but it's not always negative.
God Discipline's Those He Loves
Another meaning of punishment is "to discipline," and we know that God disciplines those whom he loves (Hebrews 12:6; Revelation 3:19).
"'For those whom the Lord loves he disciplines, as he scourges son whom he receives.' 7 It is for discipline that you endure; God deals with you as with sons; for what son is there whom his father does not discipline? 8 But if you are without discipline, of which all have become partakers, then you are illegitimate children and not sons. 9 Furthermore, we had earthly fathers to discipline us, and we respected them; shall we not much rather be subject to the Father of spirits, and live? 10 For they disciplined us for a short time as seemed best to them, but He disciplines us for our good, so that we may share His holiness. 11 All discipline for the moment seems not to be joyful, but sorrowful; yet to those who have been trained by it, afterward it yields the peaceful fruit of righteousness," (Hebrews 12:6-11).
So, if we were to say the punishment is a kind of discipline, then all Christians are punished because we are all corrected by God one way or another. Nevertheless, it's more accurate to say that all Christians are disciplined by God. Because Christians have trusted in the sacrifice of Christ on the cross, they are therefore exempt from the eternal punishment of God. The eternal punishment is damnation, or the casting of the person into hell forever (Matthew 8:12; 25:30; Revelation 14:11; 20:10). But this is not so for the Christian. This kind of punishment will never happen to the one who has faith in the atoning sacrifice of Jesus.
The reason God disciplines the Christians is that he loves us and wants us to improve our relationship with him (Matthew 22:37) and with others (Matthew 22:39). If we sin, we hinder our fellowship with God (Isaiah 59:2), and since God desires fellowship with us (1 Corinthians 1:9), he must lovingly discipline the Christian who is not walking properly before him.