Sayyiduna Abu Jum'ah (may Allah be pleased with him) narrates: We were with the Messenger of Allah (peace and blessings be upon him) on a military expedition, and Sayyiduna Abu Ubaydah bin al-Jarrah (may Allah be pleased with him) was with us. He said: O Messenger of Allah, is there anyone better than us, who accepted Islam, emigrated and strove in jihad with you? He (peace and blessings be upon him) said: "Yes, people who will come after me, who will believe in me although they will not have seen me."
Hadith Referenceالمعجم الكبير للطبراني / باب الحاء / 3526