The reason that some churches baptize infants and some do not depends upon what their understanding of baptism is and upon what conditions it is offered. Speaking generally....
The churches who not baptize infants practice "believers baptism", that is, the recipient must be of an age where they can choose to be baptized or not by themselves. They see baptism as a sign of the Christian's public profession of faith. Baptism in turn is primarily seen as a dying to sin and a rising with Christ, which is why these same churches frequently baptized by immersion.
Churches who baptize infants see baptism as a mark of God's grace freely offered to us without any preconditions on on own (such as a renunciation of sin and a choosing of Christ). It is a mark of God's love, God's claim, on the infant, and is a visible sign that the infant is included in God's family. In many churches the infants parents must be Christians and promise to bring the child up in the Christian faith.
First, it should be noted that not all Asians are Christian. Most are not. Buddhism, Shinto, and Taoism are more common in Asia, and those religions do not have a baptism ritual. As for Asian Christians, just like American Christians, there are many different denominations. Some baptize children when they are babies, others when they are older. Some baptize by sprinkling holy water on the child and saying prayers, while others require full immersion in water, sometimes in a lake or a river. They baptize people generally the same way as westerners do.
some are, but others aren't - not Christians in general
Christians strongly believe that their religion is the one true religion. Some Christians also believe that they have a duty to convert followers of all other religions, to Christianity. For some, there may even be a sense that it is in some way irrational for others not to convert readily to Christianity, when told what Christians believe. Also, it is a requirement among certain minor Christian sects and denominations for young adults to spend up to two years attempting to convert others.
Some non-Christians are called 'atheists'. Some are called 'Buddhists; others are called 'Hindus'. Others are called 'pagans'. To my knowledge, the original Bible text does NOT call anyone 'pagan'. There are Jews and Gentiles; but both of them can become Christians.
Yes, Paul did baptize some individuals during his ministry.
That depends on your church's particular beliefs. Some baptize babies after they come home from the hospital. Others wait until teenage years. Among those that baptize later on, the general view is that it is the person's commitment to Christ, not their age, that determines when they should be baptized.
Some Christians believe in witchcraft, while others do not. It varies depending on individual beliefs and interpretations of the Bible.
Christians strongly believe that their religion is the one true religion. Some have difficulty accepting that followers of other religions believe just as strongly that their own religion is the true religion. There may even be a sense for some Christians that it is in some way irrational for others not to convert readily to Christianity, when told what Christians believe.Some Christians also believe that they have a duty to convert followers of all other religions, to Christianity. Finally, it is a requirement among certain minor Christian sects and denominations for young adults to spend up to two years attempting to convert others.
Persecution of Christians, and maybe some others.
A young adult is a person who has reached maturity in some aspects but not others.
The vast majority of Pakistanis are Muslim, though there are Hindus and Christians, and others.
Christians study any were, some at schools and others at home or at a church office, there is no specific place a christan must or should as long as they do its all good.