But whoso keepeth his word, in him verily is the love of God perfected; hereby know we that we are in him.
I John 2:5
Thus, we can not only have salvation, but also assurance of salvation if we love and guard His Word, seek to keep His commandments, and love all others of like precious faith. Finally we have the indwelling witness of the Spirit. "Hereby we know that he abideth in us, by the Spirit which he hath given us. I John 3:24