The best available biblical software for concordance searching is Accordance. It is on computers throughout Bridwell Library. Many students also find it is worth the investment to buy it for their future engagement with the biblical text. Bridwell Reference Librarians can help you learn to use it.
There are several websites that allow you to perform a concordance search through older translations of the Bible that have been tagged with Strong's Concordance numbers. Be wary of other tools provided on these websites as they are provided for free. They are likely old or less scholarly than what faculty will expect for reliable source material.
An analytical or exhaustive concordance “keyed” to the version you are using (KJV, RSV, NIV, etc.) will provide the Greek or Hebrew word behind the English term you have identified and show you everywhere it occurs in the Bible.
The New Strong's Exhaustive Concordance of the Bible by 
The Analytical Concordance to the New Revised Standard Version of the New Testament by