ואני ברב חסדך אבוא ביתך
אשתחוה אל היכל קדשך ביראתך
“And I, in the abundance of Your Lovingkindness I will come into Your House;
I will bow down towards Your Holy Temple in Awe of You.” 
The above pasuk is found in many Orthodox and Conservative siddurim, to be said (after “Mah Tovu”) “on entering the synagogue” in the morning. It seems appropriate to say it, if nonessential.
But it’s the Zohar, rather than the Talmud, that specifies that we should say this at all. So, to fully understand why we say it, we must look not only at its words, but at its context in the Zohar.
“[Rabbi Shimeon bar Yochai taught]:
‘…a person should not enter the Bet Knesset without first (אמליך) — taking counsel  — of Avraham, Yitzhak and Yakov,
because it is they who instituted prayer to G-d.
‘…in the abundance of Your Lovingkindness’ are an allusion to Avraham;
‘I will bow down towards Your Holy Temple’ to Yitzhak;
‘in Awe of You’ to Yakov.
So, it is fitting to [first] link (ייעול) with them, then enter the Bet Knesset to pray one’s [own] prayers’.” 
It’s not immediately clear what the Zohar means by (אמליך), “taking counsel” with the avot.
In a parallel passage, the words (ויסב עיטא מאינון אבהן קדישין) convey the same idea.
In another parallel passage, it’s synonymous with “linking” or “including” oneself (ייעול) with the avot before entering the Bet Knesset.
Rabbi Mosheh Cordovero,  quoting the Zohar, says that one should literally recite this verse, in order to “bind oneself” – “kasher atzmo” (קשר עצמו) – to the avot.
He seems to interpret the Zohar to mean aligning ourselves affectively with the avot; becoming “one” with their intentions; with their worship; in a sense, with them.
In some way, then, “taking counsel” means being guided in worship by emulating their model. The Zohar is certainly telling us that we should prepare our minds and hearts for praying before we’ve even entered the synagogue building!
Our thoughts create an impression on the environment around us, whether we know it or not. If “actions speak louder than words…,”  then “thoughts” truly speak even louder than actions.
As the Zohar teaches us:
“Every word that comes from a person’s mouth [including our thoughts], rises and awakens a response from Above, either for good or for bad.” 
We can’t really keep our feelings a secret.
For example, when we enter a room where a sad person sits, we can feel their sadness, even if it’s not otherwise visible. Even if they’ve left the room, something of their feeling remains. This is true of any feeling, in any room: Even very young children can immediately tell if a room is filled with warmth and love, or with hostility.
Outwardly, people might seem polite. But the emotional reality invariably creates the stronger impression.
On the other hand, I once visited the “B’nai Or” (now “Aleph”) House in Philadelphia. In it was one room that was only used for quiet meditation. That room was filled with peace and silence; no other mental impression had been left there. Meditating and praying in it was a true delight. Just entering it was a holy experience.
If everyone entered their Bet Knesset with this same intention — to enter only with the thoughts that our (Biblical) Fathers & Mothers had when meeting G-d — it would help them and every other congregant to be in the best state of mind for praying.
We leave our “mark” on a room with every thought and feeling that we bring into it.
Let us, then, “take counsel with the avot,” and enter the Bet Knesset as they, themselves, entered G-d’s Presence.