Khalsa was created by His Will

Happy Vaisakhi Everyone

Khalsa which means 'pure' is the name given by Guru Gobind Singh to all Sikhs who have been baptised or initiated by taking Amrit in a ceremony called Amrit Sanchar. The first time that this ceremony took place was on Baisakhi, which fell on 30 March 1699 at Anandpur Sahib in Punjab, India. The Sikhs celebrated the 300th anniversary of the day in 1999 with thousands of religious gatherings all over the world.

In the Sikh tradition, the term appears again in one of the hukamnamas (literally written order or epistle) of Guru Hargobind (1595-1644) where a sangat of the eastern region has been described as "Guru ka Khalsa" (Guru's own or Guru's special charge). It has also been employed in the same sense in one of the letters of Guru Tegh Bahadur (1621-75) addressed to the sangat of Patna. The word occurs in Sikh Scripture, the Guru Granth Sahib, once, but there it carries the sense of the term khalis, i.e. pure.(see below)

The term "Khalsa", however, acquired a specific connotation after Guru Gobind Singh (1666-1708) introduced, on 30 March 1699, the new form of initiatory rites— khande di pahul (rites by khanda or double-edged sword). Sikhs so initiated on that Baisakhi day were collectively designated as the Khalsa — Khalsa who belonged to Vahiguru, the Supreme Lord. The phrase Vahiguru ji ka Khalsa became part of the Sikh salutation: Vahiguru ji ka Khalsa, Vahiguru ji ki Fateh (Hail the Khalsa who belongs to the Lord God! Hail the Lord God to whom belongs the victory!!)

Guru Gobind Singh, at the time of his departure from this mortal world, conferred guruship itself upon the Khalsa along with the holy Guru Granth Sahib. During the eighteenth century the volunteer force organized by the Sikhs was known as Dal Khalsa (literally the Khalsa army). Even the government of Maharaja Ranjit Singh (1780-1839) was called Sarkar-i-Khalsa. In Guru Gobind Singh's Dasam Granth, and in many later religious and historical Sikh texts, such as Sarbloh Granth, Prem Sumarg Granth, Gur Bilases, Gur Pratap Suraj Granth and Prachin Panth Prakash, the Khalsa is repeatedly extolled as composed of men of excellent moral qualities, spiritual fervour and heroism.

The words "Khalsa ji" are also used loosely for addressing an individual Singh or a group of them. However, it is more appropriate to use the term for the entire community or a representative gathering of it such as "Khalsa Panth" or "Sarbatt Khalsa." The Khalsa in this context implies the collective, spiritually-directed will of the community guided by the Guru Granth Sahib.

After 1699, the Khalsa was established as a Saint-soldier and was ordained to carry the five symbols, Panj Kakka, or the Five Ks:

Kesh – uncut hair to represent the natural appearance of sainthood. It is argued by some that the requirement is Keski instead, a small turban to be worn underneath a bigger turban. However the latter idea is not contradictory to the former, since the purpose of the Keski is to preserve the kesh.
Kanga – a small comb.
Kaccha – warrior short trousers, also denotes chastity.
Kara – steel bangle as a sign of restraint and bondage, and a symbol of dedication to the Guru. Guru Gobind Singh proclaimed that by wearing Kara all fears will be removed.
Kirpan – a sword for defence. The Kirpan is a symbol of dignity, power and courage. Kirpan is from Kirpa (act of kindness, Sanskrit) + Aan (self respect, Persian language).
He is to lead his life according to the Guru's teaching and is to respect but not practise or participate in non-Sikh religious rites or ceremonies. This includes abandoning the caste system. All Sikhs were taught to treat all in the community as equals; no distinction was to be made between the different professions or station in life.

http://sikhiwiki.org/index.php/Khalsa