Mercy of Allah Towards His Slaves
Question

How merciful is Allah, because I heard Allah loves us 70 times more than our own mothers do. Is that true? Please explain.
Praise be to Allah.Mercy of Allah
Allah is the Most Merciful , Most Compassionate, and He is the Most Merciful of those who show mercy. His Mercy encompasses all things. Allah says (interpretation of the meaning): 
“… and My Mercy embraces all things.” [Al-A`araf 7:156] 
In Sahih Muslim, Abu Hurayrah (may Allah be pleased with him) narrated that the Prophet (peace and blessings of Allah be upon him) said: “Allah has one hundred parts of mercy, of which He sent down one between the jinn, mankind, the animals and the insects, by means of which they are compassionate and merciful to one another, and by means of which wild animals are kind to their offspring. And Allah has kept back ninety-nine parts of mercy with which to be merciful to His slaves of the Day of Resurrection.” (Muslim, al-Tawbah, 6908) 
‘Umar ibn al-Khattab (may Allah be pleased with him) said: “Some prisoners were brought to the Messenger of Allah (peace and blessings of Allah be upon him), and there was a woman among the prisoners who was searching (for her child). When she found her child she embraced him and put him to her breast. The Messenger of Allah (peace and blessings of Allah be upon him) said to us, ‘Do you think that this woman would throw her child in the fire?’ We said, ‘No, by Allah, not if she is able not to.’ The Messenger of Allah (peace and blessings of Allah be upon him) said, ‘Allah is more merciful to His slaves than this woman is to her child.’”  (Agreed upon)
Aspects of the mercy of Allah towards His slaves
One aspect of the Mercy of Allah to His slaves is that He sent the messengers and revealed the Books and laws to organize their lives according to the ways of wisdom, far removed from hardship and difficulty. Allah says (interpretation of the meaning): 
“And We have sent you (O Muhammad) not but as a mercy for the ‘alamin (mankind, jinn and all that exists).” [Al-Anbiya 21:107] 
The Mercy of Allah is what will admit His believing slaves to Paradise on the Day of Resurrection. No one will ever enter Paradise because of his deeds alone, as the Prophet (peace and blessings of Allah be upon him) said: “No one’s deeds will ever admit him to Paradise.” They said, “Not even you, O Messenger of Allah?” He said, “No, not even me, unless Allah showers me with His Mercy. So try to be near to perfection. And no one should wish for death; he is either doing good so he will do more of that, or he is doing wrong so he may repent.” [Al-Bukhari, Muslim] 
So the believer must remain in a state between hoping for the Mercy of Allah and fearing His punishment, for Allah says (interpretation of the meaning): 
“Declare (O Muhammad) unto My slaves, that truly, I am the Oft-Forgiving, the Most-Merciful. And that My Torment is indeed the most painful torment.” [Al-Hijr 15:49-50] 
With regard to your saying that Allah loves us more than seventy mothers, Allah knows best concerning that. It is sufficient for us to know that the Mercy of Allah encompasses all things. O Allah, have mercy upon us, O Most Merciful of those who show mercy.
And Allah knows best.