The Quran

وَجاهِدوا فِي اللَّهِ حَقَّ جِهادِهِ ۚ هُوَ اجتَباكُم وَما جَعَلَ عَلَيكُم فِي الدّينِ مِن حَرَجٍ ۚ مِلَّةَ أَبيكُم إِبراهيمَ ۚ هُوَ سَمّاكُمُ المُسلِمينَ مِن قَبلُ وَفي هٰذا لِيَكونَ الرَّسولُ شَهيدًا عَلَيكُم وَتَكونوا شُهَداءَ عَلَى النّاسِ ۚ فَأَقيمُوا الصَّلاةَ وَآتُوا الزَّكاةَ وَاعتَصِموا بِاللَّهِ هُوَ مَولاكُم ۖ فَنِعمَ المَولىٰ وَنِعمَ النَّصيرُ

Muhammad Asad

And strive hard in God's cause with all the striving that is due to Him: it is He who has elected you [to carry His message], and has laid no hardship on you in [anything that pertains to] religion,¹ [and made you follow] the creed of your forefather Abraham.² It is He who has named you - in bygone times as well as in this [divine writ] - "those who have surrendered themselves to God",³ so that the Apostle might bear witness to the truth before you, and that you might bear witness to it before all mankind. Thus, be constant in prayer, and render the purifying dues, and hold fast unto God. He is your Lord Supreme: and how excellent is this Lord Supreme, and how excellent this Giver of Succour!

The absence of any "hardship" in the religion of Islam is due to several factors: (1) it is free of any dogma or mystical proposition which might make the Qur'anic doctrine difficult to understand or might even conflict with man's innate reason; (2) it avoids all complicated ritual or system of taboos which would impose undue restrictions on man's everyday life; (3) it rejects all self-mortification and exaggerated asceticism, which must unavoidably conflict with man's true nature (cf. in this connection note 118 on the first sentence of 2:143); and (4) it takes fully into account the fact that "man has been created weak" (4:28).
Abraham is designated here as "your forefather" not only because he was, in fact, an ancestor of the Prophet Muhammad - to whose followers this passage is addressed - but also because he is the prototype (and thus, the spiritual "forefather") of all who consciously "surrender themselves to God" (see next note).
The term muslim signifies "one who surrenders himself to God"; correspondingly, islam denotes "self-surrender to God". Both these terms are applied in the Qur'an to all who believe in the One God and affirm this belief by an unequivocal acceptance of His revealed messages. Since the Qur'an represents the final and most universal of these divine revelations, the believers are called upon, in the sequence, to follow the guidance of its Apostle and thus to become an example for all mankind (cf. 2:143 and the corresponding note 119).