Hazart Abu bakr (R.A) was always a nearby Companion of the Holy Prophet (PBUH). His original name is Abdullah ibn Abi Qhuhafah. He knew him better than some other man.
He knew how fair and upright the Prophet Muhammad (PBUH) was. Such information of the Prophet made Abu Bakr (R.A) is the first man to take after the Message of Prophet Muhammad (PBUH).
He was to be sure the first grown-up male to acknowledge Islam. He was also First Muslim caliph. He (R.A) was such a close friend that Hazart Muhammad (PBUH) said in his last days...
“This Hadith has been narrated through another chain of transmitters and the one narrated on the authority of Abdullah (the words are):
“Allah’s Messenger (ﷺ) is reported to have said: Behold I am free from the dependence of all bosom friends and if I were to choose anyone as bosom friend I would have taken Abu Bakr as my bosom friend. Allah has taken your companion as a friend.”
Life before Islam:
Hazart Abu Bakr (R.A) was quite and sincere man. He was very trustworthy person. He belongs to Nobel family. These properties make him different from other. His (R.A) kindness also won heart of Hazart Muhammad (PBUH).They become friends in early boyhood. He (R.A) was very soft hearted person. He always tries to help the poor.
He (R.A) was the first man who accepts Islam. When holly prophet (PBUH) disclose to him secretly about the revelation of ALLAH (SWT) Hazart Abu Bakr (R.A) accepted Islam without any hesitation. Holly Prophet once said that:
"When I invited people towards Allah, everybody thought over it and hesitated, at least for a while, except Abu Bakr who accepted my call the moment I put it before him, and he did not hesitate even for a moment.”
As He (R.A) accepted Islam he starts preaching Islam. He daily visit different people and invite them. So he was also second who preach Islam. He (R.A) was also the companion of cave. He surfed Islam in all his possible ways. He was commander in battle of baddar. After the Ascension in the 10th year He (PBUH) narrated in the morning. Some of them came of Hazart Abu Bakr (R.A) and they told that what holly prophet (PBUH) is saying. He (R.A) said if He (PBUH) is saying then its truth. For this Holly Prophet (PBUH) named him as-Saddiq.
After a fortnight's disease, As-Siddiq al-Akbar passed away at 61 years old on the 22nd Jamadal-Akhira. Prior to his demise he said to his girl Lady 'Aisha (R.A), "Don't utilize new fabric for my cover. Wash the sheet in my utilization and wrap my body in it". His wish was followed up on. His next wish was to pay all the cash he got as compensation for Caliph from "Baitul Mal" (The Public Treasury) in the wake of offering his arrangement. He said, I didn't prefer to take anything from the "Baitul Mal however Umar pressed me to acknowledge some remittance so I would be soothed of my occupation and give my full time to the obligations of the Khilafat (Caliphate). I was left no decision however to acknowledge the offer". After his demise 'Aisha asked Hazrat Umar to assume control over that arrangement as craved by her father. Umar remarked: "May Allah bless him. He left no chance for anybody to open his lips against him".