The word "merciful" means being kind and forgiving, showing mercy and compassion towards others instead of being harsh or punishing them. Full definition
My copy of the Koran opens «In the name of the most merciful God,» but certainly the meaning that God is love is there. (religion-online.org)
And grant, O most merciful Father, for his sake, that we may hereafter live a godly, righteous, and sober life; to the glory of thy holy name. (religion-online.org)
But Bother Moses and Jesus proclaimed God as merciful as well. (redeeminggod.com)