According to the Bible, is it in accordance to the will of God to wear gold or silver chains? Is it good to wear a cross with a replica of Jesus on it? How about one that is just a gold or silver cross?

The bible tells us that people of God wore jewelry. (Exodus 35:22 Then all whose hearts moved them, both men and women, came and brought brooches and earrings and signet rings and bracelets, all articles of gold; so did every man who presented an offering of gold to the LORD.) It is never condemned by God. In the New Testament Paul and Peter warn people not to wear anything in access or for the purpose of showing off their possessions. (1 Peter 3:1-4 ....Your adornment must not be merely external-- braiding the hair, and wearing gold jewelry, or putting on dresses; but let it be the hidden person of the heart, with the imperishable quality of a gentle and quiet spirit, which is precious in the sight of God. 1 Timothy 2:9 Likewise, I want women to adorn themselves with proper clothing, modestly and discreetly, not with braided hair and gold or pearls or costly garments,) Peter and Paul are not condemning wearing jewelry or dresses, but saying that our heart our lives should be what people look at when they see us and not our possessions. I cannot see why it would be wrong for one to wear a cross necklace unless one does it for show. In Bible times people would write scriptures in a little box called phylacteries tie them around their forehead or forearm and keep them on them to remind them of God (Deuteronomy 6:8-9 You shall bind them as a sign on your hand and they shall be as frontals on your forehead. You shall write them on the doorposts of your house and on your gates). By the days of Jesus some began to try to let everyone know how religious they were by enlarging these and Jesus condemned this ( Matthew 23:5 But they do all their deeds to be noticed by men; for they broaden their phylacteries and lengthen the tassels of their garments.) I would suggest that if one decides to wear a cross, a WWJD bracelet, a t-shirt, or any other religious symbols that they keep the right spirit and remember that our lives and our heart should be sufficient to let people know that we are Christians and the other should be used as a reminder to us of who we belong to.

Is it a sin to wear shorts?

Your question is somewhat ambiguous because shorts is a relative term.  Shorts are many different lengths. We are taught in the scriptures to adorn ourselves in modest apparel (1 Timothy 2:9). Any apparel that appears suggestive in nature could be considered immodest. Clothes too tight might be immodest but cover the entire body. Many shorts are longer than some dresses and would be more modest than such dresses. What the world calls short shorts are not any more comfortable to wear than knee length shorts and if such shorts are being worn solely to get the opposites sex's attention we might reconsider whether it is appropriate to wear such. The Lord expects us to use good judgment when it comes to such matters and most of us can readily ascertain when something is immodest. If it is immodest, yes it is sinful, if it falls into the category of being modest feel free to wear the same.

What does the bible say about how men should dress in church?

The importance of the heart of the worshiper is emphasized throughout the entire Bible (Psm. 132:9, Psm. 24:3, 4, Exodus 31:10). God was also concerned about the actual garments worn by these men of pure
hearts. In Exodus and Leviticus, God described their physical garments as "clothes of service".
In our society our dress often reflects our hearts. Schools have school uniforms. Criminals appear in court in new suits and groomed to perfection!

There is no Divine code for dress in worship, but our culture has one!  Why do people "dress up" to attend weddings? Why is it that people "dress up" for funerals? Why is it that people "dress up" when they have a chance
to be with governors or presidents? Our culture sets these standards, and to fail to live by these standards shows disrespect for the event our those who are honored by their attendance.  When we come to have an audience with the Creator, we show disrespect to Him if we fail to "dress up" for the occasion. There is no place for sloven
dress at such times. Visitors to our services are aprt of the culture and they will readily understand how little or how much respect we have for worship based on what we wear.  What does it mean to "dress up"? It is not the attire you'd wear to a picnic, to work in the yard, or to simply "hang out." It is the attire, you'd wear if you knew you were making one of the most important public appearances of your life.
 

What does the bible say about wearing earrings?

The Bible tells us that people wore earrings and other jewelry. The
Israelites took their jewelry and gave it as an offering for the tabernacle
(Exodus 35:22 Then all whose hearts moved them, both men and women, came
and brought brooches and earrings and signet rings and bracelets, all
articles of gold; so did every man who presented an offering of gold to the
LORD.) Jewelry was often given to a woman to be married. We can see this
when Isaac and Rebecca were to be married (Genesis 24:22 When the camels
had finished drinking, the man took a gold ring weighing a half-shekel and
two bracelets for her wrists weighing ten shekels in gold). When we come to
the New Testament we know people wore jewelry because the apostles Paul and
Peter give Christian women some instructions concerning them. 1 Timothy
2:9-10 tells the women to be humble, to wear things that are fitting the
occasion, and to wear things in moderation. This passage is in reference to
jewelry. 1 Peter 3:3-4 instructs women to not let jewelry be the only thing
that makes them beautiful and attractive but their hearts should be the
center of their beauty.  No where in the Bible does it forbid wearing
earrings or other jewelry. The Bible tells us not to show off our wealth or
be wear so much jewelry that people focus on it more than you.