Rev Koosimile was born on the 20th of April 1972 in Molepolole, Kweneng District of Botswana. He is the third born child of Mr Boitswarelo and Mrs Semakaleng Koosimile, with four sisters and three brothers. On the 6th of December 1997 he married Monei Rachel Koosimile nee Sereetsi and they are blessed with 2 children: a boy Obakeng Victor and a girl Katlego Joy.

He has been in the ministry since 1995 and was ordained as a Pastor in August 1996. As an ordained Pastor he served at the following AFM Assemblies in Botswana: Bobonong 1995-1998, Mochudi 1999-2006, Serowe 2008-2012 and Thamaga from 2012 to date. In January 2007 he was assigned to missionary work in Ireland until April 2008, this was because of his leadership skills and dedication to work.

Rev Koosimile holds a Bachelor of Theology from Tripp Bible Institute (USA) and a Bachelor of Theological Studies from Vision International University (USA). He has also done a three-year Ministerial Diploma at the Central Bible College in South Africa. In 1991 Reverend Jobe completed his Cambridge Overseas Secondary Certificate (COSC) in his home village of Molepolole where he grew up, and did his lower academic level.

He has been serving as the AFM President of Botswana since 2013 to date, overseeing 102 assemblies in the country. He is the Vice President of the AFMI. With regards to AFM Botswana, he also served on the following Ministerial Portfolios: Vice President (2001-2006), Re-Elected Vice President (2009-2013), National Youth leader in AFM Botswana (1997-2002) and was then elected in 2013 as President.

Other Portfolios he served on outside of The AFM Botswana include President of Botswana Christian Aids Intervention Programs – BOCAIP (2015-2017) and re-elected for a new term (2019-2021) as President. He became the Vice President of the Evangelical Fellowship Botswana – EFB (2015-2017) and was later elected as President (2017-2019). EFB is an organisation that oversees and coordinates the evangelical Pentecostal and Charismatic churches in Botswana. He also served as the Chairperson of: the Mochudi Prison Visiting Committee, the Kgatleng District Council Child Welfare Committee, the Minister’s Fraternal Mochudi and the Minister’s Fraternal Serowe. Lastly, in 2005 he was licensed as a Marriage Officer and still holds the licence to date.

His ministry and passion to serve compels him to work closely with Non-Governmental organisations, Dikgosi (Chiefs), Village District Committees, the elderly and young people. Hence, he facilitated the Adolescence Sexual Reproduction & Health Workshops and worked with youth groups such as the Youth For Christ in Botswana, Scripture Union (SU) and the Unashamed Movement.