How do we love God?

Today, we continue to read 1 John 4:19-5:4
John continues to explain his idea of loving God through loving our brothers.
First of all, we are able to love because someone has loved us first. This someone is God "We love; because He first love us ἡμεῖς ἀγαπῶμεν, ὅτι αὐτὸς πρῶτος ἠγάπησεν ἡμᾶς"(1 John 4:19).
Secondly, no man has seen God. Therefore, how can we prove that we love God? Love our brothers! "... for he who does not love his brother whom he has seen, cannot love God whom he has not seen ὁ γὰρ μὴ ἀγαπῶν τὸν ἀδελφὸν αὐτοῦ ὃν ἑώρακεν, τὸν θεὸν ὃν οὐχ ἑώρακεν οὐ δύναται ἀγαπᾶν" (1 John 4:20).

When we read this verse casually, we definitely agree with John and probably think that he has proved that to love God, we must love our brothers. No. Not yet! Even if this statement of John is true, it is not very encouraging because its negation does not guarantee that we can love God.
This is a simple exercise of logic. Given "If P then Q", we cannot conclude that "not P then not Q". So, let P be (he does not love his brother) and Q be (he cannot love God). 1 John 4:20 can be expressed as "If P then Q". Sadly, we cannot conclude that "not P then not Q" which is "if he loves his brother, he can love God". In John's own words, we cannot draw the conclusion that we love God when we love our brothers! We can only say that we love our brothers if we love God.
So, where is the ground for John's position that we love God through loving our brothers? This is expressed as a commandment, not as a conditional: And this commandment we have from him, that he who loves God should love his brother also (1 John 4:21). When it is a commandment from God, it allows for no exceptions. (The previous statement is shaky because God forbids killing men in the Ten Commandments, but in real world, sometimes we must kill in order to save lives and to protect the innocent!)  Loving God is equated with loving one's brothers. We show our love of God by obeying His commandments (1 John 5:2).
How do we know God's commandments? From the Bible. God gave His commandments to Moses to pass them on to the Israelites.  This is the Old Testament. In these last days, God spoke to us through Jesus (Hebrews 1:2). This is the New Testament. Christians see the fulfillment of all the promises God made in the time of Old Testament in the New.
This epistle of John has a particular theology. Earlier on, the author of this epistle talks about keeping Jesus' commandments as if they are God's commandments. He also talks about perfecting our love for God and about abiding in Jesus (1 John 2:3-6). Therefore, the epistle as a whole, does not attempt to distinguish vigorously between Jesus and God. Now, life becomes easier for Christians because they don't have to worship a God who cannot be perceived through their senses. They have a more tangible Jesus instead. Jesus did not claim his divine status in order to make God more accessible to mankind. Now, by keeping Jesus' commandments, Christians are obeying God's commandments. They are loving God.
Shung Tak is a Catholic Diocesan school in Hong Kong. However, her religious atmosphere is thin. Religious Studies as a public examination subject is not popular like Economics or Physics. Students are pragmatic and find little utility in RS. The school administration is not putting enough effort in uplifting the morale, not to mention the mission of evangelization. School administrators are apologetic for the inconvenience caused by the religion of the school and are always ready to concede. Religion is dispensable.
Example #1:
As a Catholic school, RS used to be a compulsory public examination subject offered to all 5 classes of S5. Two of them study science. There was one stronger class which took Additional Maths. The weaker class had no Additional Maths and took Computer Studies instead. In order to boost the result of CS in the public exam.,  the school 'yielded' to the demand from the stronger class to have the best of both worlds. The students wanted to take both Add. Maths. and CS. As a result, the school allowed the stronger class to drop RS in order to take CS. Religion is dispensable.
Example #2:
When I first came to Shung Tak, the RS panel-chair told me that the school did not respect RS. I thought respect had to be earned. Catholic teachers in the school should work in more visible ways to allow their faith to shine forth.
Later, I discovered that the Principal did not get along well with the parish priest and took the earliest opportunity to move the school away from the church to the present site where the nearest chapel is a 10-minute walk away. I further discovered that despite the heavy marking load of RS paper (9 pieces of composition), it is always assigned near the end of S5 Mock Examination schedule. The administration has a very laudable and legitimate reason: they simply follow the public exam schedule! My God! Only a tiny percentage of candidates in Hong Kong take RS. So it is reasonable to assign RS to a later time. But here in Shung Tak, 80% of students take the subject!
A Catholic school should tell her students that she takes RS seriously. The proper place of RS in the mock exam schedule should be the first! Religion is indispensable.

My God. You know my frustrations through and through. Grant me strength so that I may be able to suffer humbly for Your sake. Bestow on me patience and faith so that I may continue to love my students you have entrusted in my hand. Be with me so that I will be able to love and support my colleagues. Amen