By definition a Saintly person is dear to God so as Bhagwan says in Bhagwad Gita 12.20
ये तु धर्म्यामृतमिदं यथोक्तं पर्युपासते।
श्रद्दधाना मत्परमा भक्तास्तेऽतीव मे प्रियाः।।12.20।।
Those who follow this imperishable path of devotional service and who completely engage themselves with faith, making Me the supreme goal, are very, very dear to Me. BG 12.20
So from this we can conclude that a Bhakta is a saintly person or vice versa, from Bhagwad Gita verse 12.13 to 12.19 Bhagwan gives the characteristics of a Bhakta or a Noble man who is dear to him.
The characteristics/qualities of Noble man or a Saint/Sadhu are as follows
Refer BG-12.13
He never hates any being even though they hate him and do him wrong.
He is ‘friendly’, evincing a friendly disposition towards all beings whether they hate him or do him wrong.
He is free from the ‘feeling of mine’.
He is free from the feeling of ‘I’, i.e., is free from the delusion that
his body is the self.
pain and pleasure are the same to him (inference from previous quality).
He is ‘enduring’, unaffected even by those two (i.e., pleasure and pain) due to the inevitable contact of sense-objects(refered to as Kshami
).
Refer BG-12.14
He is ‘content’(santushta).
He ‘ever meditates,’ i.e., is constantly intent on contemplating on the self as separate from the body.
He is ‘self-restrained’, namely, he controls the activities of his mind.
He is of ‘firm conviction’ regarding the meanings taught in the science of the self.
Refer BG-12.15
He does not become the cause of ‘fear to the world’.
He has no cause to ‘fear the world’.
He is not in the habit of showing favour towards someone and intolerance towards others.
He has no fear of some or repulsion for others.
ReferBG-12.16
He has no longing for anything except the self.
Who is ‘pure’, namely, whose body is nourished on the food prescribed by the Sastras(refer BG-3.13).
Who is an expert in performing actions prescribed by the Sastras aka Dharma Vetta.
Who is ‘indifferent’, i.e., not interested in matters other than those enjoined by the Sastras.
Who is free from ‘agony’.
Who renounces all ‘undertakings,’ i.e., who renounces all undertakings except those demanded by the Sastras.
Refer BG-12.17
He who does not ‘rejoice’, i.e., that Karma Yogin, who, on obtaining things which cause joy to man, does not rejoice.
Who does not ‘hate’, does not hate on obtaining anything undesriable.
Who is not ‘grieved’ by common sorrows which cause grief among men.
Who ‘does not desire’ anything like fortune.
Who ‘renounces good and evil,’ i.e., who renounces both merit and demerit because, like demerit, merit also causes bondage, there being no difference between them in this respect.
Refer BG-12.18-12.19
The absence of hate etc., towards foes, friends etc.
he is ‘same even in honour and dishonour.’
Who is always free from contaminating association.
Who has no ‘home’, namely, who is not attached to home, etc.
Always silent and satisfied with anything.
Who is fixed in knowledge and who is engaged in devotional service.
If you ever encounter anyone with aforementioned qualities/characteristics fall onto his feet, and don't leave his feet until he shows you the Moksha Marga, Road that leads to enlightenment.
IMO very few gurus/spiritual leaders fall in this category and they are to be worshipped as gods, few examples are Bhagwad Ramanujacharya, Adi Shankaracharya, Vedanta Deshikacharya, Shri Hanuman, Shri Bheeshma, HatiRam Baba, current Sri Vaishnava and Advaita Mathadhipatis(Shankaracharyas) etc and the list goes on.