traividyaa maam somapaahaa pootapaa yajnairishtvaa svargatim praarthayante |
te punyamaasaadya surendralokamashnanti divyaandivi devabhoogaan || 20 ||

Those well-versed in the three Vedas, after worshipping me through sacrifices, and drinking nectar and purified of sin, they pray for attainment of heaven. Having obtained merits, they enjoy the divine pleasures of the gods in heaven.
traividyaa : those well versed in three Vedas
maam : me
somapaahaa : drinkers of nectar
pootapaahaa : purified of sin
yajnaihi : through sacrifices
ishtvaa : after worship
svargatim : to attain heaven
praarthayante : pray
te : they
punyam : merits
aasaadya : obtain
surendralokam : abode of Indra
ashnanti : enjoy
divyaan : divine
divi : heavenly world
devabhoogaan : pleasures of the gods
Having described the infinite nature of Ishvara, Shri Krishna now elaborates upon the topic of devotees or bhaktas. There are predominantly two types of devotees: desire-oriented (sakaama) and desireless (nishkaam). Desire-oriented devotees are described in these two shlokas. Note the change to a longer meter to emphasize a change in the topic.
Who is the desire-oriented bhakta? He is a devotee who worships Ishvara for a material gain. He either wants merits (punya), wealth (artha), earthly joy (sukha), heavenly joy (svaraga) or a combination of these four. In simple words he is looking for money, name and fame.
So for example, if someone wants to buy a car, they pray that it is the right price and that it is in stock. If someone has an exam, they pray that they pass in the exam. Vedas and rituals mentioned in this shloka refer to the efforts that we put into appeasing Ishvara. We may not perform elaborate rituals, but there always is a thought that “please God let this happen so that I can be happy”, which amounts to the same thing as the rituals mentioned here.
Now, when a child asks his parents for something insignificant, a parent feels frustrated because the parent has the capability to give much greater value, but cannot do so because the child insists on that insignificant thing. Similarly, Ishvara also may feel sometimes that the things we ask of him – wealth, heavenly pleasures and so on – are insignificant. Such people do not have a strong resolve towards liberation, they do not have the “vyavasaatmikaa buddhi” mentioned in chapter 2. Their focus is diverted away from Ishvara towards material pursuits.
Assuming they somehow accumulate merits and attain heaven, what happens next?